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        <title>MathCity.org</title>
        <description>Merging man &amp; maths</description>
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        <item>
            <title>Question 13 Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-2-p9</link>
            <description>Question 13 Exercise 6.2

Solutions of Question 13 of Exercise 6.2 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$\mathrm{E}$$n=10$$m_1=4$$E, m_2=2$$L$$m_3=2$$C$\begin{align}\text{total number of permutations are}
 &amp;=\left(\begin{array}{c}
n \\
m_1, m_2, m_3
\end{array}\right)\\&amp;=\left(\begin{array}{c}
10 \\
4,2,2
\end{array}\right) \\
&amp; =\dfrac{10 !}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:41 +0000</pubDate>
        </item>
        <item>
            <title>Unit 06: Permutation, Combination and Probability (Solutions)</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06</link>
            <description>Unit 06: Permutation, Combination and Probability (Solutions)

This is a sixth unit of the book Mathematics 11 published by Khyber Pakhtunkhwa Textbook Board, Peshawar, Pakistan. On this page we have provided the solutions of the questions.

After reading this unit the students will be able to$n$$n!$$n$$r$$^nP_r$$n$$r$$n$$r$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:34:51 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 and 6 Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-2-p3</link>
            <description>Question 5 and 6 Exercise 6.2

Solutions of Question 5 and 6 of Exercise 6.2 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$7.$$7$$7$\begin{align}^7 P_7&amp;=\dfrac{7 !}{(7-7) !}\\
&amp; =7 !\\
&amp;=5,040 \end{align}$2,4,5,7,9$$2,4,5,7,9$$\mathrm{n} . \mathrm{m}$$e$$$=5.4 .3 .2=120\quad \text{or}$$$$^5 P_4=\dfrac{5 !}{5-4} !=120$$$2$$4$$3$$E_1$$m_1=2$$E_2$$m_2=3…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:36 +0000</pubDate>
        </item>
        <item>
            <title>Question 9 &amp; 10 Review Exercise 6</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/re-ex6-p6</link>
            <description>Question 9 &amp; 10 Review Exercise 6

Solutions of Question 9 &amp; 10 of Review Exercise 6 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$2,3,0,3,4,2,3$$1$$=100,0000$$$=\dfrac{7 !}{3 ! \cdot 2 !}=420 $$$1$$0$$7$$0$$$=\dfrac{6 !}{2 ! 3 !}=60 $$$1$$420-50=360$$n$$n$$(n-1)$$(n - 1)$$(n-1)$$(n-2) !$$2$$2 !$$n$$$(n-2) ! \cdot 2 !=2(n-2) ! $$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:03 +0000</pubDate>
        </item>
        <item>
            <title>Multiple Choice Questions (MCQs)</title>
            <link>https://www.mathcity.org/math-11-kpk/mcqs</link>
            <description>Multiple Choice Questions (MCQs)

Here are the sample MCQs at this time. Page will be updated periodically. 

SAMPLE MCQs

	*  $i^{13}=$.............
		*  (A) $i$
		*  (B) 1
		*  (C) -1
		*  (D) 2

	*  Set of all possible subsets of $S$ is called
		*  (A) Equivalent sets$1, \omega, \omega^2$$-1, \omega, \omega^2$$-1, -\omega, -\omega^2$$1, -1, 2$$ax^2+bx+c=0$$a=0, b\neq 0$$a\neq 0$$a=b=0$$b=$$ax^2+bx+c=0$$a=0, b\neq 0$$a\neq 0$$a=b=0$$b=$$n!=n(n-1)(n-2)...3\cdot 2\cdot 1$$n$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 05 Dec 2023 02:44:44 +0000</pubDate>
        </item>
        <item>
            <title>Question 1 and 2 Exercise 6.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-1-p1</link>
            <description>Question 1 and 2 Exercise 6.1

Solutions of Question 1 and 2 of Exercise 6.1 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$\dfrac{10 !}{3 ! .3 ! \cdot 4 !}$\begin{align}\dfrac{10 !}{3 ! \cdot 3 ! \cdot 4 !}&amp;=\dfrac{10.9 .8 \cdot 7 \cdot 6 \cdot 5.4 !}{3 ! \cdot 3 ! \cdot 4 !}\\
&amp;=\dfrac{10.9 .8 .7 .5}{3.2 .1}\\
&amp;=4200 \end{align}$\dfrac{3 !+4 !}{5 !-…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:32 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 &amp; 4 Exercise 6.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-1-p2</link>
            <description>Question 3 &amp; 4 Exercise 6.1

Solutions of Question 3 &amp; 4 of Exercise 6.1 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$\dfrac{1}{6 !}+\dfrac{2}{7 !}+\dfrac{3}{8 !}=\dfrac{75}{8 !}$\begin{align}\dfrac{1}{6 !}+\dfrac{2}{7 !}+\dfrac{3}{8 !}&amp;=\dfrac{1}{6 !}+\dfrac{2}{7.6 !}+\dfrac{3}{8.7 .6 !} \\
&amp; =\dfrac{56+16+3}{8 !}\\
&amp;=\dfrac{75}{8 !}\end{align}$\df…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:30 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 Exercise 6.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-1-p3</link>
            <description>Question 5 Exercise 6.1

Solutions of Question 5 of Exercise 6.1 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$\dfrac{(2 n) !}{n !}=2^n(1.3 .5 \ldots(2 n-1))$\begin{align}\dfrac{(2 n) !}{n !}&amp;=\dfrac{1}{n !}[(2 n)(2 n-1)(2 n-2) \\
&amp;=(2 n-3)(2 n-4)(2 n-5) \ldots(2 n-(2 n-4))\\
&amp;(2 n-(2 n-3))(2 n-(2 n-2))(2 n-(2 n-1))]\end{align}$2 n$\begin{align}\dfra…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:32 +0000</pubDate>
        </item>
        <item>
            <title>Question 4 Exercise 6.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-1-p4</link>
            <description>Question 4 Exercise 6.1

Solutions of Question 4 of Exercise 6.1 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:33 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 Exercise 6.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-1-p5</link>
            <description>Question 5 Exercise 6.1

Solutions of Question 5 of Exercise 6.1 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:33 +0000</pubDate>
        </item>
        <item>
            <title>Question 1 and 2 Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-2-p1</link>
            <description>Question 1 and 2 Exercise 6.2

Solutions of Question 1 and 2 of Exercise 6.2 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$^6 P_6$\begin{align}^6 P_6&amp;=\dfrac{6 !}{(6-6) !}\\
&amp;=6 !=720\end{align}$^{20} P_2$\begin{align}^{20} P_2&amp;=\dfrac{20 !}{(20-2) !}\\
&amp;=\dfrac{20.19 .18 !}{18 !}\\
&amp;=20 \times 19=380\end{align}$^{16} P_3$\begin{align}^{16} P_3&amp;=\dfr…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:35 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 and 4 Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-2-p2</link>
            <description>Question 3 and 4 Exercise 6.2

Solutions of Question 3 and 4 of Exercise 6.2 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$^n P_r=n(^{n-1} P_{r-1})$$$^n P_r=n({ }^{n-1} P_{r-1})$$\begin{align}n(^{n-1} P_{r-1})&amp;=n \dfrac{(n-1) !}{((n-1)-(r-1)) !} \\
&amp; =\dfrac{n(n-1) !}{(n-r) !}\\
&amp;=\dfrac{n !}{(n-r) !}\\
&amp;=^n P_r\end{align}$^n P_r=^{n-1} P_r+r(^{n-1} …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:37 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 and 8 Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-2-p4</link>
            <description>Question 7 and 8 Exercise 6.2

Solutions of Question 7 and 8 of Exercise 6.2 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$1,2,3,4$$E_1$$m_1=5$$E_2$$\cdot m_2=5$$E_3$$m_3=5$$$m_1 \cdot m_2 \cdot m_3=5.5 \cdot 5=125$$$1,2,3,4$$E_1$$m_1=5$$E_2$$m_2=4$$E_3$$m_3=3$$$m_1 \cdot m_2 \cdot m_3=5 \cdot 4 \cdot 3=60$$$8$$5$$=4$$=4$$=5$$=3$$4 ! \cdot 5 ! \cdot …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:38 +0000</pubDate>
        </item>
        <item>
            <title>Question 9 Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-2-p5</link>
            <description>Question 9 Exercise 6.2

Solutions of Question 9 of Exercise 6.2 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$=^6 P_1=6$$s=^6 P_2=30$$=^6 P_3=120$$=^6 P_4=360$$=^6 P_5=720$$=^6 P_6=720$$6+30+120+360+720+720=1956$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:38 +0000</pubDate>
        </item>
        <item>
            <title>Question 10 Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-2-p6</link>
            <description>Question 10 Exercise 6.2

Solutions of Question 10 of Exercise 6.2 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$n=8$$r=5$\begin{align}^8 P_5&amp;=\dfrac{8 !}{(8-5) !}\\
&amp;=\dfrac{8 \cdot 7 \cdot 6 \cdot 5 \cdot 4 \cdot 3 !}{3 !}\\
&amp;=6720\end{align}\begin{align}^2 P_2 \times^7 P_4&amp;=2 \times \dfrac{7 !}{(7-4) !}\\
&amp;=2 \times\dfrac{7.6 .5 .4 .3 !}{3 !}\\
&amp;=…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:40 +0000</pubDate>
        </item>
        <item>
            <title>Question 11 Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-2-p7</link>
            <description>Question 11 Exercise 6.2

Solutions of Question 11 of Exercise 6.2 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$10$$1000$$2.3,4,0,8,9$$10$$1000$$10$$100$$E_1$$m_1=5$$E_2$$m_2=5$$10$$100$$$m_1 \cdot m_2=5.5=25$$$100$$1000$$0$$E_1$$m_1=5$$E_2$$\boldsymbol{m}_2=5$$E_3$$m_3=4$$100$$1000$$$m_1 \cdot m_2 \cdot m_3=5.5 \cdot 4=100$$$10$$1000$$$100 + 25=125…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:40 +0000</pubDate>
        </item>
        <item>
            <title>Question 12 Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-2-p8</link>
            <description>Question 12 Exercise 6.2

Solutions of Question 12 of Exercise 6.2 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$8.$$n=8$$\mathrm{O}$$m_1=3$\begin{align}
 \left(\begin{array}{c}
n \\
m 1
\end{array}\right)&amp;=\left(\begin{array}{l}
8 \\
3
\end{array}\right) \\
&amp; =\dfrac{8 !}{3 !}\\
&amp;=\dfrac{8 \cdot 7 \cdot 6 \cdot 5 \cdot 4 \cdot 3 !}{3 !}\\
&amp;=6,720 \e…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:41 +0000</pubDate>
        </item>
        <item>
            <title>Question 14 and 15 Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-2-p10</link>
            <description>Question 14 and 15 Exercise 6.2

Solutions of Question 14 and 15 of Exercise 6.2 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$$\dfrac{(n-1) !}{2}=\dfrac{(5-1) !}{2}=\dfrac{24}{2}=12 $$$7$$7$$6 !$$6$$5!$$2 !=2$$7$$$2 \times 5 !=240$$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:35 +0000</pubDate>
        </item>
        <item>
            <title>Question 1 Exercise 6.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-3-p1</link>
            <description>Question 1 Exercise 6.3

Solutions of Question 1 of Exercise 6.3 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$^n C_2=36$$n$\begin{align}&amp;^n C_2=36\\
&amp; \Rightarrow \dfrac{n !}{(n-2) ! 2 !}=36 \\
&amp; \Rightarrow \dfrac{n(n-1)(n-2) !}{(n-2) ! \cdot 2}=36 \\
&amp; \Rightarrow n(n-1)=72 \\
&amp; \Rightarrow n^2-n-72=0 \\
&amp; \Rightarrow n^2-9 n+8 n-72=0\\
&amp; \Rightar…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:43 +0000</pubDate>
        </item>
        <item>
            <title>Question 2 Exercise 6.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-3-p2</link>
            <description>Question 2 Exercise 6.3

Solutions of Question 2 of Exercise 6.3 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$n$$r$${ }^n P_r=840$${ }^n C_r=35$\begin{align}
&amp;^n P_r=\dfrac{n !}{(n-r) !}=840 ....(i)\\
&amp;^n C_r=\dfrac{n !}{(n-r) ! r !}=35....(ii)\end{align}\begin{align}\dfrac{n !}{(n-r) !} \cdot \dfrac{(n-r) ! r !}{n !}&amp;=\dfrac{840}{35}\\
r!&amp;=24\\
\te…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:43 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 Exercise 6.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-3-p3</link>
            <description>Question 3 Exercise 6.3

Solutions of Question 3 of Exercise 6.3 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$n$$^{2 n} C_3:^n C_2=36: 3$\begin{align}
&amp; { }^{2 n} C_3:{ }^n C_2=36: 3 . \\
&amp; \Rightarrow \dfrac{(2 n) !}{(2 n-3) ! 3 !} \times \dfrac{(n-2) ! 2 !}{n !}=12 \\
&amp; \Rightarrow \dfrac{2 n(2 n-1)(2 n-2)(2 n-3) !}{(2 n-3) ! 3 !}\times\dfrac{(n-2…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:45 +0000</pubDate>
        </item>
        <item>
            <title>Question 4 Exercise 6.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-3-p4</link>
            <description>Question 4 Exercise 6.3

Solutions of Question 4 of Exercise 6.3 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.${ }^{n-1} C_r+{ }^{n-1} C_{r-1}={ }^n C_r$$${ }^n{ }^1 C_r+{ }^n{ }^1 C_{r-1}={ }^n C_s$$\begin{align}
{ }^{n-1} C_r+{ }^{n-1} C_{r-1}&amp;=\dfrac{(n-1) !}{(n-r-1) ! r !}+\dfrac{(n-1) !}{(n-1-(r-1)) !(r-1) !} \\
&amp; =\dfrac{(n-1) !}{(n-r-1) ! r(r-…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:46 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 and 6 Exercise 6.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-3-p5</link>
            <description>Question 5 and 6 Exercise 6.3

Solutions of Question 5 and 6 of Exercise 6.3 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$12$$n=12$${ }^{12} C_2=66$$12$$n=12$${ }^{12} C_3=220$$${ }^6 C_2=\dfrac{6 !}{(6-2) ! 2 !}=15 $$$6$$\quad 15-6=9$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:46 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 and 8 Exercise 6.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-3-p6</link>
            <description>Question 7 and 8 Exercise 6.3

Solutions of Question 7 and 8 of Exercise 6.3 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$20$\begin{align}{ }^{20} C_2&amp;=\dfrac{20 !}{(20-2)2!}!\\
&amp;=\dfrac{20!}{18!\cdot 2!}\\
&amp;=190\end{align}$7$$10$$3$$7$$10$$${ }^{10} C_7=\dfrac{10 !}{(10-7) ! 7 !}=120$$$7$$4.$$4$$${ }^7 C_4=\dfrac{7 !}{(7-4) ! 4 !}=35.$$$35$$10.$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:47 +0000</pubDate>
        </item>
        <item>
            <title>Question 9 Exercise 6.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-3-p7</link>
            <description>Question 9 Exercise 6.3

Solutions of Question 9 of Exercise 6.3 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$8$$6$$7$$7$$6.$$=7+6=13$${ }^7 C_4$${ }^6 C_4$\begin{align}{ }^7 C_4 \cdot{ }^6 C_4&amp;=\dfrac{7 !}{(7-4) ! 4 !} \cdot \dfrac{6 !}{(6-4)}\\\
&amp;= 525\end{align}$8$$6$$7$$7$$6$$=7+6=13$$3,4,5,6$$6$\begin{align}{ }^7 C_2 \cdot{ }^6 C_6&amp;=\dfrac{7 !}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:48 +0000</pubDate>
        </item>
        <item>
            <title>Question 9 Exercise 6.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-3-p8</link>
            <description>Question 9 Exercise 6.3

Solutions of Question 9 of Exercise 6.3 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:48 +0000</pubDate>
        </item>
        <item>
            <title>Question 1 Exercise 6.4</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-4-p1</link>
            <description>Question 1 Exercise 6.4

Solutions of Question 1 of Exercise 6.4 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$S=\{1,2,3,4,5,6\}$$5$$5$\begin{align}A&amp;=\{5\}\\
P(A)&amp;=\dfrac{n(A)}{n(S)}\\
&amp;=\dfrac{1}{6} \end{align}$S=\{1,2,3,4,5,6\}$$1$$1$\begin{align}B&amp;=\{\}\\
&amp;=\phi \text{then}\\
P(B)&amp;=\dfrac{n(B)}{n(S)}\\
&amp;=\dfrac{0}{6}\\
&amp;=0\end{align}$S=\{1,2,3,4,…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:49 +0000</pubDate>
        </item>
        <item>
            <title>Question 2 Exercise 6.4</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-4-p2</link>
            <description>Question 2 Exercise 6.4

Solutions of Question 2 of Exercise 6.4 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$4$$5$$6$$3$$4+5+6=15$$${ }^{15} C_3=\dfrac{15 !}{(15-3) ! 3 !}=455 $$$${ }^6 C_4=\dfrac{6 !}{(6-4) ! 4 !}=15$$$$=\dfrac{15}{455}=\dfrac{3}{91}$$$4$$5$$6$$3$$4+5+6=15$$${ }^{15} C_3=\dfrac{15 !}{(15-3) ! 3 !}=455 $$$${ }^4 C_3=\dfrac{4 !}{(4-…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:50 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 Exercise 6.4</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-4-p3</link>
            <description>Question 3 Exercise 6.4

Solutions of Question 3 of Exercise 6.4 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$8$$8$$2^8$$$n(S)=256$$$$\dfrac{1}{256}$$$8$$$A=\{8\}$$$${ }^8 C_8=\dfrac{8 !}{(8-8) ! 8 !}=1$$$8$$$P(A)=\dfrac{1}{256}$$$7$$8$$2^8$$$n(S)=256$$$$\dfrac{1}{256}$$$7$$$B=\{7\}$$$7$$8$$$n(B)={ }^8 C_7=\dfrac{8 !}{(8-7) ! 7 !}=8$$$7$$8$$$P(B)=\d…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:51 +0000</pubDate>
        </item>
        <item>
            <title>Question 4 Exercise 6.4</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-4-p4</link>
            <description>Question 4 Exercise 6.4

Solutions of Question 4 of Exercise 6.4 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.\begin{align}S&amp;=(HHII,HHT.HTH.HTT.THII.THT.TTH,TT7),\\
\text{then} n(S)&amp;=2^3=8\end{align}$$A=\{H H H\}$$$$n(A)=1$$$P(A)=\dfrac{n(A)}{n(S)}=\dfrac{1}{8}$\begin{align}S&amp;=(HHII,HHT.HTH.HTT.THII.THT.TTH,TT7),\\ 
\text{then} n(S)&amp;=2^3=8\end{align}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:52 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 Exercise 6.4</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-4-p5</link>
            <description>Question 5 Exercise 6.4

Solutions of Question 5 of Exercise 6.4 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$6$$4$$3$$2$$=6+4=10$$5$$10$\begin{align}{ }^{10)} C_5 &amp;=\dfrac{10 !}{(10-5) ! 5 !}\\
&amp;=252\\ 
n(S)&amp;=252\end{align}$3$$2$$3$$2$\begin{align}{ }^6 \mathrm{C}_3\cdot{ }^{4} \mathrm{C}_2&amp;=\dfrac{6 !}{(6-3) ! 3 !} \cdot \dfrac{4 !}{(4-2) ! 2 !}\\…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:52 +0000</pubDate>
        </item>
        <item>
            <title>Question 6 Exercise 6.4</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-4-p6</link>
            <description>Question 6 Exercise 6.4

Solutions of Question 6 of Exercise 6.4 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$52$$$=52$$$=4$$$=\dfrac{4}{52}=\dfrac{1}{13}$$$52$$=52$$13$$13$$$\dfrac{13}{52}+ \dfrac{13}{52}=\dfrac{1}{4}+\dfrac{1}{4}=\dfrac{2}{4}=\dfrac{1}{2}$$$52$$=52$$13.$$$=\dfrac{13}{52}=\dfrac{1}{4}$$$52$$=52$$12.$$$=\dfrac{12}{52}=\dfrac{3}{13}$…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:53 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 Exercise 6.4</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-4-p7</link>
            <description>Question 7 Exercise 6.4

Solutions of Question 7 of Exercise 6.4 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.\begin{align}S&amp;=\{(i, j) ; i, j=1,2,3,4,5,6\}\\
&amp;=\left[\begin{array}{llllll}
(1,1) &amp; (1,2) &amp; (1,3) &amp; (1,4) &amp; (1,5) &amp; (1,6) \\
(2,1) &amp; (2,2) &amp; (2,3) &amp; (2,4) &amp; (2,5) &amp; (2,6) \\
(3,1) &amp; (3,2) &amp; (3,3) &amp; (3,4) &amp; (3,5) &amp; (3,6) \\
(4,1) &amp; (4,2) &amp; (…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:53 +0000</pubDate>
        </item>
        <item>
            <title>Question 1 and 2 Exercise 6.5</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-5-p1</link>
            <description>Question 1 and 2 Exercise 6.5

Solutions of Question 1 and 2 of Exercise 6.5 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$A$$B$$P(A)=\dfrac{2}{5}, P(B)=\dfrac{2}{5}$$P(A \cup B)=\dfrac{1}{2}$$P(A \cap B)$\begin{align}
 P(A \cup B)&amp;=P(A)+P(B)-P(A \cap B) \\
 \Rightarrow P(A \cap B)&amp;=P(A)+P(B)-P(A \cup B)
\end{align}$P(A), P(B)$$P(A \cup B)$$$P(A \cap…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:54 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 and 4 Exercise 6.5</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-5-p2</link>
            <description>Question 3 and 4 Exercise 6.5

Solutions of Question 3 and 4 of Exercise 6.5 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$P(A)=0.5$$P(A \cup B)=0.6$$P(B)$$A$$B$$\mathrm{A}$$B$$A \cap B=\emptyset$\begin{align}P(A \cup B)&amp;=P(A)+P(B)\\
\Rightarrow P(B)&amp;=P(A \cup B)-P(A)\\
&amp;=0.6-.0 .5=0.1 \end{align}$30$$1$$30.$\begin{align}S&amp;=\{1,2,3, \ldots, 50\} \tex…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:55 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 and 6 Exercise 6.5</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-5-p3</link>
            <description>Question 5 and 6 Exercise 6.5

Solutions of Question 5 and 6 of Exercise 6.5 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$\dfrac{8}{9}$$$E=\{ event\, passing\, the\, test \}$$$$E^{\prime}=\{ event\, failing\, the\, test \}$$$E$$E^{\prime}$$P(E)=\dfrac{8}{9}$\begin{align}P(E^{\prime})&amp;=1-P(E)=1-\dfrac{8}{9}=\dfrac{1}{9}\end{align}$4$$4$\begin{align}S…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:56 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 Exercise 6.5</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-5-p4</link>
            <description>Question 7 Exercise 6.5

Solutions of Question 7 of Exercise 6.5 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$52$$52$$26$$26$$13$$13$$13$$13$$13$$10,9,8,7,6,5,4,3$$2.$$$=\dfrac{13}{52}=\dfrac{1}{4}$$$$=\dfrac{4}{52}=\dfrac{1}{13}$$\begin{align}
P(A \cup B)&amp;=P(A)+P(B) \\
&amp; =\dfrac{1}{4}+\dfrac{1}{13}=\dfrac{17}{52} \end{align}$$=1-\dfrac{17}{52}=\dfr…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:56 +0000</pubDate>
        </item>
        <item>
            <title>Question 8 Exercise 6.5</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-5-p5</link>
            <description>Question 8 Exercise 6.5

Solutions of Question 8 of Exercise 6.5 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$7$$11.$\begin{align}s&amp;=(i i, j): i, j-1,2,3,4,5,6\}\\
&amp;=\left[\begin{array}{llllll}
(1.1) &amp; (1.2) &amp; (1.3) &amp; (1.4) &amp; (1.5) &amp; (1.6) \\
(2.1) &amp; (2.2) &amp; (2.3) &amp; (2.4) &amp; (2.5) &amp; (2.6) \\
(3.1) &amp; (3.2) &amp; (3.3) &amp; (3.4) &amp; (3.5) &amp; (3.6) \\
(4.1) &amp; (4…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:57 +0000</pubDate>
        </item>
        <item>
            <title>Question 9 Exercise 6.5</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-5-p6</link>
            <description>Question 9 Exercise 6.5

Solutions of Question 9 of Exercise 6.5 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$2$$\dfrac{1}{7}$$\dfrac{1}{5}$\begin{align}
P(\text { Ajmal scicction })&amp;=\dfrac{1}{7} \\
\Rightarrow P(\text { Ajmal not selected })&amp;=\dfrac{6}{7} \\
P(\text { Bushra selection })&amp;=\dfrac{1}{5} \\
\Rightarrow P(\text { Bushra not selected }…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:57 +0000</pubDate>
        </item>
        <item>
            <title>Question 10 Exercise 6.5</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/ex6-5-p7</link>
            <description>Question 10 Exercise 6.5

Solutions of Question 10 of Exercise 6.5 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$20$$10$$5$$3$$2$$=20$$=10$$=5$$=3$$=15$$=5$$=10$$=3$$=22$$E$$a A$$B$$2$\begin{align}n(S)&amp;={ }^{30} C_2\\
&amp;=435\\
P(A)&amp;=\dfrac{^{20} C_2}{^{30} C_2}\\
&amp;=\dfrac{190}{435}=\dfrac{38}{87}\\
P(B)&amp;=\dfrac{^{22} C_2}{^{30} C_2}\\
&amp;=\dfrac{231}{43…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:58 +0000</pubDate>
        </item>
        <item>
            <title>Question 1 Review Exercise 6</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/re-ex6-p1</link>
            <description>Question 1 Review Exercise 6

Solutions of Question 1 of Review Exercise 6 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$O, P, Q, R, S, T, U$$2520$$9040$$5140$$4880$$2520$$\{1,2,3,4,5,6,7\}$$14$$42$$28$$21$$28$$\{1,2,3,4,6,7,8\}$$3$$7$$120$$180$$144$$96$$120$$\dfrac{(n+2) !(n-2) !}{(n+1) !(n-1) !}$$(n-3)$$(\dot{n}-1)$$\dfrac{n+1}{n+2}$$\dfrac{n+2}{n-…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:35:59 +0000</pubDate>
        </item>
        <item>
            <title>Question 2 Review Exercise 6</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/re-ex6-p2</link>
            <description>Question 2 Review Exercise 6

Solutions of Question 2 of Review Exercise 6 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.${ }^{2 n} C_r={ }^{2 n} C_{r+2}$$r$\begin{align}
{ }^{2 n} C_r&amp;={ }^{2 n} C_{r+2} \\
\Rightarrow \dfrac{(2 n) !}{(2 n-r) ! r !}&amp;=\dfrac{(2 n) !}{(2 n-(r+2)) !(r+2) !}\end{align}$(2 n)$\begin{align}
\Rightarrow \dfrac{1}{(2 n-r) ! r…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:00 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 &amp; 4 Review Exercise 6</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/re-ex6-p3</link>
            <description>Question 3 &amp; 4 Review Exercise 6

Solutions of Question 3 &amp; 4 of Review Exercise 6 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.${ }^{56} P_{r+6}:{ }^{54} P_{r+3}=30800: 1$$r$\begin{align}
{ }^{56} P_{r+6}:{ }^{54} P_r+3&amp;=30800: 1  \\
\Rightarrow \dfrac{\dfrac{56 !}{[56-(r+6)] !}}{\dfrac{54 !}{[54-(r+3)] !}}&amp;=\dfrac{30800}{1} \\
\Rightarrow \dfrac{56…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:00 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 &amp; 6 Review Exercise 6</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/re-ex6-p4</link>
            <description>Question 5 &amp; 6 Review Exercise 6

Solutions of Question 5 &amp; 6 of Review Exercise 6 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$$n=6$$$$(n-1) !=(6-1) !=5 !=120$$$120-24=96$$n=6$$(n-1) !=(6-1) !=5 !=120$$$(n-1) !=(5-1) !=4 !=24$$$$(n-1) !=(6-1) !=5 !=120$$$$4 ! \cdot 2 !=48$$$(5-1) !$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:01 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 &amp; 8 Review Exercise 6</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/re-ex6-p5</link>
            <description>Question 7 &amp; 8 Review Exercise 6

Solutions of Question 7 &amp; 8 of Review Exercise 6 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$P(A)=0.8, P(B)=0.5$$P(B / A)=0.4$$P(A \cap B)$\begin{align}
P(B \mid A)&amp;=\dfrac{P(A \cap B)}{P(A)} \\
\Rightarrow P(A \cap B)&amp;=P(B \mid A) \cdot P(A)\\
&amp;=0.4 \times 0.8=0.32\end{align}$P(A)=0.8, P(B)=0.5$$P(B / A)=0.4$$P(A …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:01 +0000</pubDate>
        </item>
        <item>
            <title>Question 11 Review Exercise 6</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit06/re-ex6-p7</link>
            <description>Question 11 Review Exercise 6

Solutions of Question 11 of Review Exercise 6 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$$n(S)=4$$$\dfrac{1}{4}$$$\quad P( orange )=\dfrac{1}{4}$$$\dfrac{1}{4}$$\dfrac{1}{4}$\begin{align}P(\operatorname{Red})&amp;=\dfrac{1}{4}\\
P( Green )&amp;=\dfrac{1}{4}\end{align}$P(R \cap G)=\phi$$R$$G$\begin{align}\boldsymbol{P}( Red o…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:03 +0000</pubDate>
        </item>
        <item>
            <title>Question 1 Exercise 7.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-1-p1</link>
            <description>Question 1 Exercise 7.1

Solutions of Question 1 of Exercise 7.1 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$2+4+6+\cdots+2 n=n(n+1)$$n=1$$$2=1(1+1)=2 $$$n=1$$n=k$$$2+4+6+\cdots+2 k=k(k+1)....(i)$$$n=k+1$$(k+1)^{t h}$$$a_{k+1}=\mathbf{2}(k+1)=2 k+2 $$$k+1$\begin{align}2+4+6+\cdots+2 k+2(k+1)&amp; =k(k+1)+2(k+1) \\
&amp; =(k+1)[k+2] \\
&amp; =(k+1)(k+1+1)\end{a…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:07 +0000</pubDate>
        </item>
        <item>
            <title>Question 2 Exercise 7.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-1-p2</link>
            <description>Question 2 Exercise 7.1

Solutions of Question 2 of Exercise 7.1 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$1+5+9+\ldots+(4 n-3)=n(2 n-1)$$n=1$$$1=1(2.1-1)=1$$$n=1$$n=k$\begin{align}1+5+9+\ldots+(4 k-3)\\
&amp; =k(2 k-1)....(i) \\
\end{align}$n=k+1$$k+1$$$a_{k-1}=4(k+1)-3=4 k+1 $$$(k+1)^{t h}$\begin{align}1+5+9+\ldots+(4 k-3)+(4 k+1)&amp; =k(2 k-1)+4 k+1 …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:12 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 Exercise 7.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-1-p3</link>
            <description>Question 3 Exercise 7.1

Solutions of Question 3 of Exercise 7.1 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$3+6+9+\ldots+3 n=\dfrac{3 n(n+1)}{2}$$n=1$$3=\dfrac{3.1(1+1)}{2}=3$$n=1$$n=k$$$3+6+9+\ldots+3 k=\dfrac{3 k(k+1)}{2}....(i)$$$n=k+1$$(k+1)$$a_{k+1}=3(k+1)$$(k+1)^{t h}$\begin{align}3+6+9+\ldots+3 k+3(k+1) &amp; =\dfrac{3 k(k+1)}{2}+3(k+1) \\
&amp; =3…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:13 +0000</pubDate>
        </item>
        <item>
            <title>Question 4 Exercise 7.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-1-p4</link>
            <description>Question 4 Exercise 7.1

Solutions of Question 4 of Exercise 7.1 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$3+7+11+\cdots+(4 n-1)=n(2 n+1)$$n=1$$$3=1(2+1)=3 $$$n=1$$n=k$\begin{align}3+7+11+\cdots+(4 k-1) 
&amp; =k(2 k+1)....(i) \end{align}$n=k+1$$(k+1)$$a_{k+1}=4(k+1)-1$$(k+1)^{t h}$\begin{align}
3+7+11+\cdots+(4 k-1)+[4(k+1)-1] &amp; =k(2 k+1)+4(k+1)-1 \…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:13 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 Exercise 7.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-1-p5</link>
            <description>Question 5 Exercise 7.1

Solutions of Question 5 of Exercise 7.1 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$1^3+2^3+3^3+\ldots+n^3=\left[\dfrac{n(n+1)}{2}\right]^2$$n=1$$1^3=1=\left[\dfrac{1(1+1)}{2}\right]^2=1$$n=1$$n=k_1$\begin{align}1^3+2^3+3^3+\ldots+k^3&amp; =[\dfrac{k(k+1)}{2}]^2....(i)\end{aligned}
3. Now $$ the $$ term of the given series on l…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:14 +0000</pubDate>
        </item>
        <item>
            <title>Question 6 Exercise 7.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-1-p6</link>
            <description>Question 6 Exercise 7.1

Solutions of Question 6 of Exercise 7.1 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$1(1 !)+2(2 !)+3(3 !)+\ldots+n(n !)= -(n+1) !-1$$n=1$$$1(1 !)=1=(1+1) !-1=2 !-1=1 $$$n=1$$n=k$\begin{align}1(1 !)+2(2 !)+3(3 !)+\ldots+k(k !)&amp; =(k+1) !-1  \ldots . .(i)\end{align}$n=k+1$$(k+1)^{t h}$$a_{k+1}=(k+1)[(k+1) !]$$a_{k-1}$\begin{ali…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:14 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 Exercise 7.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-1-p7</link>
            <description>Question 7 Exercise 7.1

Solutions of Question 7 of Exercise 7.1 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$1.2+2.3+3.4+\ldots+n(n+1)=\dfrac{n(n+1)(n+2)}{3}$$n=1$$$1.2=2=\dfrac{1(1+1)(1+2)}{3}=2 $$$n=1$$n=k$\begin{align}1.2+2.3+3.4+\ldots+k(k+1)&amp; =\dfrac{k(k+1)(k+2)}{3}....(i)\end{align}$n=k+1$$(k-1)^{t h}$$a_{k+1}=(k+1)(k+ 2)$$(k+1)^{\text {th }}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:19 +0000</pubDate>
        </item>
        <item>
            <title>Question 8 Exercise 7.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-1-p8</link>
            <description>Question 8 Exercise 7.1

Solutions of Question 8 of Exercise 7.1 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$1+2+2^2+2^3+\ldots+2^n 1=2^n-1$$n=1$$1=2^1-1=1$$n=1$$n-k&gt;1$\begin{align}1+2+2^2+2^3+\ldots+2^{k-1} \\
&amp; =2^k-1 ....(i)\end{align}$n-k-1$$(k+1)^{t h}$$a_{k+1}=2^k$$a_{k+1}$\begin{align}1+2+2^2+2^3+\ldots+2^{k-1}-2^k &amp; =2^k-12^k \\
&amp; =2^k+2^k-…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:19 +0000</pubDate>
        </item>
        <item>
            <title>Question 9 Exercise 7.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-1-p9</link>
            <description>Question 9 Exercise 7.1

Solutions of Question 9 of Exercise 7.1 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$\dfrac{1}{3}+\dfrac{1}{9}+\dfrac{1}{27}+\ldots+\dfrac{1}{3^n}=\dfrac{1}{2}[1-\dfrac{1}{3^n}]$$n=1$$$\dfrac{1}{3}-\dfrac{1}{2}[1-\dfrac{1}{3}]-\dfrac{1}{2} \dfrac{2}{3}=\dfrac{1}{3} $$$n=1$$n=k$$$\dfrac{1}{3}+\dfrac{1}{9}+\dfrac{1}{27}+\ldots…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:21 +0000</pubDate>
        </item>
        <item>
            <title>Question 10 Exercise 7.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-1-p10</link>
            <description>Question 10 Exercise 7.1

Solutions of Question 10 of Exercise 7.1 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$\left(\begin{array}{1}5 \\5 \end{array}\right)+\left(\begin{array}{l}6 \\ 5\end{array}\right)+\left(\begin{array}{l}7 \\ 5\end{array}\right)+\ldots+\left(\begin{array}{c}n+4 \\ 5\end{array}\right)=\left(\begin{array}{c}n+5 \\ 6\end{array}\…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:07 +0000</pubDate>
        </item>
        <item>
            <title>Question 11 Exercise 7.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-1-p11</link>
            <description>Question 11 Exercise 7.1

Solutions of Question 11 of Exercise 7.1 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.\begin{align}
&amp; \left(\begin{array}{l}
2 \\
2
\end{array}\right)+\left(\begin{array}{l}
3 \\
2
\end{array}\right)+\left(\begin{array}{l}
4 \\
2
\end{array}\right)+\ldots+\left(\begin{array}{l}
n \\
2
\end{array}\right)=\left(\begin{array}{c…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:08 +0000</pubDate>
        </item>
        <item>
            <title>Question 12 Exercise 7.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-1-p12</link>
            <description>Question 12 Exercise 7.1

Solutions of Question 12 of Exercise 7.1 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$\dfrac{5^{2 n}-1}{24}$$n=1$$$\dfrac{5^{2 n}-1}{24}=\dfrac{5^{2.1}-1}{24}=\dfrac{24}{24}=1 \in \mathbb{Z}$$$n=1$$n=k&gt;1$$$\dfrac{5^{2 k}-1}{24} \in \mathbb{Z}$$$n=k+1$\begin{align}\dfrac{5^{2(k+1)}-1}{24}&amp;=\dfrac{5^{2 k+2}-1}{24} \\
&amp; =\dfra…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:09 +0000</pubDate>
        </item>
        <item>
            <title>Question 13 Exercise 7.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-1-p13</link>
            <description>Question 13 Exercise 7.1

Solutions of Question 13 of Exercise 7.1 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$2^n&gt;n \forall n \in \mathbf{N}$$n=1$$2^n=2^1=2$$n=1$$2&gt;1$$n=1$$n=l&gt;I$$2^k&gt;k\cdots(i)$$n=k+1$\begin{align}
&amp; 2^{k+1}=2^k \cdot 2&gt;k \cdot 2 \quad \text { by (i) } \\
&amp; \Rightarrow 2^{k+1}&gt;2 k=k+k \\
&amp;\Rightarrow 2^{k+1}&gt;k+1 \text {. as } k&gt;1…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:10 +0000</pubDate>
        </item>
        <item>
            <title>Question 14 Exercise 7.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-1-p14</link>
            <description>Question 14 Exercise 7.1

Solutions of Question 14 of Exercise 7.1 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$5$$3^{2 n-1}+2^{2 n-1}$$n$$n=1$$$3^{2 n-1}+2^{2 n-1}=3^{2.1-1}+2^{2.1-1}=5 \text {. }$$$5$$5$$5$$5.$$n=1$$n=k&gt;1$$54$$3^{2 k} 1+2^{2 k} \quad 1$$$3^{2 k-1}+2^{2 k-1}=5 Q$$$Q$$n=k+1$\begin{align}
3^{2(k+1)-1}+2^{2(k+1)-1} &amp; =3^{2 k+2-1}+2^{2…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:10 +0000</pubDate>
        </item>
        <item>
            <title>Question 15 Exercise 7.1</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-1-p15</link>
            <description>Question 15 Exercise 7.1

Solutions of Question 15 of Exercise 7.1 of Unit 06: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$a+b$$a^n-b^n$$n$$n$$n=2 n, \quad m \in \mathbb{Z}^{+}$$m=1$$$a^{2 n}-b^{2 m}=a^2-b^2=(a+b)(a-b)$$$\Rightarrow(a+b)$$a^2-b^2$$m=1$$n=2$$m=k$$$a^{2 k}-b^{2 k}=Q(a+b)$$$Q$$m=k+1$\begin{align}a^{2(k+1)}-b^{2(k-1)} &amp; =a^{2 k+2}-b^{2 k+2} \\
&amp; =…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:12 +0000</pubDate>
        </item>
        <item>
            <title>Question 1 Exercise 7.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-2-p1</link>
            <description>Question 1 Exercise 7.2

Solutions of Question 1 of Exercise 7.2 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$(x^2-\dfrac{1}{y})^4$\begin{align}(x^2-\dfrac{1}{y})^4&amp;=(x^2)^4+{ }^4 C_1(x^2)^3(-\dfrac{1}{y})+ \\
&amp; { }^4 C_2(x^2)^2(-\dfrac{1}{y})^2+{ }^4 C_3(x^2)(-\dfrac{1}{y})^3 + { }^4 C_4(-\dfrac{1}{y})^4 \\
&amp; =x^8- \dfrac{4x^6}{y}+\dfrac{6x^4}{y^2}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:21 +0000</pubDate>
        </item>
        <item>
            <title>Question 2 Exercise 7.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-2-p2</link>
            <description>Question 2 Exercise 7.2

Solutions of Question 2 of Exercise 7.2 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$4^{th}$$(2+a)^7$$\ln$$n=7$$a=2$$b=a$$$T_{r+1}=\frac{7 !}{(7-r) ! r !}(2)^{7-r } a^r $$$4^{\text {th }}$$r=3$\begin{align}
&amp; T_{3+1}=\dfrac{7 !}{(7-3) ! 3 !} 2^{7-3} a^3 \\
&amp; \Rightarrow T_4=\dfrac{7 !}{4 ! 3 !} \cdot 2^4 a^3 \\
&amp; \Rightarrow…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:23 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 Exercise 7.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-2-p3</link>
            <description>Question 3 Exercise 7.2

Solutions of Question 3 of Exercise 7.2 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$x$$(\dfrac{4 x^2}{3}-\dfrac{3}{2 x})$$n=9, \quad a=\dfrac{4 x^2}{3}$$b=-\dfrac{3}{2 x}$$T_{r+1}$$x$$T_{r+1}$\begin{align}T_{r+1}&amp;=\dfrac{9 !}{(9-r) ! r !}(\dfrac{4 x^2}{3})^{9-r}(-\dfrac{3}{2 x})^r \\
&amp; =\dfrac{9 !}{(9-r) ! r !} \cdot \dfrac…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:24 +0000</pubDate>
        </item>
        <item>
            <title>Question 4 Exercise 7.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-2-p4</link>
            <description>Question 4 Exercise 7.2

Solutions of Question 4 of Exercise 7.2 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$x^{23}$$(x^2-x)^{20}$$n=20, \quad a=x^2$$b=-x$$T_{r, 1}$$x^{23}$\begin{align}T_{r-1}&amp;=\dfrac{20 !}{(20-r) ! r !}(x^2)^{20 r}(-x)^r \\
&amp; =\dfrac{20 !}{(20-r) ! r !}(-1)^r \cdot x^{40-2 r+r} \\
&amp; =\dfrac{20 !}{(20-r) ! r !}(-1)^r x^{40-r}\end{…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:25 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 Exercise 7.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-2-p5</link>
            <description>Question 5 Exercise 7.2

Solutions of Question 5 of Exercise 7.2 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$(\dfrac{a}{x}+b x)^8$$a=\dfrac{a}{x}$$b=b x$$n=8$$n-8$$8+1=9$$$(\dfrac{8+2}{2})^{t h}=5^{t h}$$T_{r+1}$$$T_{r+1}=\dfrac{8 !}{(8-r) ! r !}(\dfrac{a}{x})^{8-r}(b x)^r$$$T_5$$r=4$\begin{align}T_5&amp;=\dfrac{8 !}{(8-4) ! 4 !}(\dfrac{a}{x})^{8-4}(b …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:25 +0000</pubDate>
        </item>
        <item>
            <title>Question 6 Exercise 7.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-2-p6</link>
            <description>Question 6 Exercise 7.2

Solutions of Question 6 of Exercise 7.2 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$(2 \sqrt{x}-\dfrac{3}{x \sqrt{x}})^{23}$$a=2 \sqrt{x}$$b=-\dfrac{3}{x \sqrt{x}}$$n=23$$x$\begin{align}
T_{r+1}&amp;=\dfrac{23 !}{(23-r) ! r !}(2 \sqrt{x})^{23-r}(-\dfrac{3}{x \sqrt{x}})^r \\
&amp; =\dfrac{23 !}{(23-r) ! r !} \cdot 2^{23-r} \cdot(-3)…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:27 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 Exercise 7.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-2-p7</link>
            <description>Question 7 Exercise 7.2

Solutions of Question 7 of Exercise 7.2 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$(2+\sqrt{3})^5+(2-\sqrt{3})^5$\begin{align}(2+\sqrt{3})^5+(2 \cdot \sqrt{3})^5&amp; =[(2)^5+{ }^5 C_1 \cdot 2^4 \cdot \sqrt{3}+{ }^5 C_2 \cdot 2^3 \cdot(\sqrt{3})^2 \\
&amp; +^5 C_3 \cdot 2^2 \cdot(\sqrt{3})^4+{ }^5 C_4 \cdot 2 \cdot(\sqrt{3})^4 \\
…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:27 +0000</pubDate>
        </item>
        <item>
            <title>Question 8 Exercise 7.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-2-p8</link>
            <description>Question 8 Exercise 7.2

Solutions of Question 8 of Exercise 7.2 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$(3-2 x)^{10}$$x=\frac{3}{4}$$\left(3-2,1^{10}=3^{10}\left(1-\frac{3 x}{2}\right)^{10}\right.$$\left(1-\frac{3 x}{2}\right)^{10}$$p+1$$: 3-\mathbf{2}_1 1^{10}$$T_{5} !=\left(\begin{array}{c}10 \\ 5\end{array}\right) 3^{10} 5-2 \gamma^{15}$$x=…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:28 +0000</pubDate>
        </item>
        <item>
            <title>Question 9 Exercise 7.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-2-p9</link>
            <description>Question 9 Exercise 7.2

Solutions of Question 9 of Exercise 7.2 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$(x-y)=&quot;$$x=12$$y-4$$x=12$$$
\begin{aligned}
&amp; \left(x \quad y=20(12-y)^{20}\right. \\
&amp; =12^{2 n}\left(\begin{array}{ll}
1 &amp; \frac{y}{12}
\end{array}\right)^{31}
\end{aligned}
$$$\frac{(n+1) \cdot x}{1+|x|}$$\left(\frac{1}{12}\right)^2 \cdot…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:28 +0000</pubDate>
        </item>
        <item>
            <title>Question 10 Exercise 7.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-2-p10</link>
            <description>Question 10 Exercise 7.2

Solutions of Question 10 of Exercise 7.2 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$n=2 ;$$s=2^{n-1}$$$
\left.(1+x)^n=\left(\begin{array}{l}
n \\
\vdots
\end{array}\right)+\left(\begin{array}{l}
m \\
1
\end{array}\right) x+\left(\begin{array}{l}
n \\
2
\end{array}\right) x^2-\ldots+i_n^*\right) x^n \cdot
$$$x=1$$(1 \div 1…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:22 +0000</pubDate>
        </item>
        <item>
            <title>Question 11 Exercise 7.2</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-2-p11</link>
            <description>Question 11 Exercise 7.2

Solutions of Question 11 of Exercise 7.2 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$(1+x)^n$$\left(\begin{array}{l}n \\ r\end{array}\right)=\mathrm{C}_r$$\mathrm{C}_1+2 \mathrm{C}_2 x+3 \mathrm{C}_3 x^2+\ldots \ldots . .+\mathrm{nC}_{\mathrm{n}} x^{\mathrm{n}-1}=\mathrm{n}(1+x)^{\mathrm{n}-1}$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:22 +0000</pubDate>
        </item>
        <item>
            <title>Question 1 Exercise 7.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-3-p1</link>
            <description>Question 1 Exercise 7.3

Solutions of Question 1 of Exercise 7.3 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$\frac{1}{2}$$$
\begin{aligned}
&amp; (1-x)^{\frac{1}{2}}=1+\frac{1}{2} x+ \\
&amp; \frac{\frac{1}{2}\left(-\frac{1}{2}-1\right)}{2 !}(-x)^2
\end{aligned}
$$$$
\begin{aligned}
&amp; +\frac{-\frac{1}{2}\left(-\frac{1}{2}-1\right)\left(-\frac{1}{2}-2\right…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:29 +0000</pubDate>
        </item>
        <item>
            <title>Question 2 Exercise 7.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-3-p2</link>
            <description>Question 2 Exercise 7.3

Solutions of Question 2 of Exercise 7.3 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$\sqrt{26}$$$
\begin{aligned}
&amp; \sqrt{26}=\sqrt{25+1} \\
&amp; =\sqrt{25} \sqrt{1+\frac{1}{25}}=5\left[1+\frac{1}{25}\right]^{\frac{1}{2}}
\end{aligned}
$$$$
\begin{aligned}
&amp; \sqrt{26}=5\left[1+\frac{1}{25}\right]^{\frac{1}{2}} \\
&amp; =5\left[1+\f…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:32 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 Exercise 7.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-3-p3</link>
            <description>Question 3 Exercise 7.3

Solutions of Question 3 of Exercise 7.3 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$\sqrt{\frac{1-x}{1+x}}$$x^3$$\sqrt{\frac{1-x}{1+x}}$$$
=(1-x)^{\frac{1}{2}}(1+x)^{-\frac{1}{2}} \text {. }
$$$$
\begin{aligned}
&amp; (1-x)^{\frac{1}{2}}(1+x)^{\frac{1}{2}} \\
&amp; =\left[1-\frac{x}{2}+\frac{\frac{1}{2}\left(\frac{1}{2}-1\right)}{2…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:33 +0000</pubDate>
        </item>
        <item>
            <title>Question 4 Exercise 7.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-3-p4</link>
            <description>Question 4 Exercise 7.3

Solutions of Question 4 of Exercise 7.3 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$x$$x^2$$x$$$
\sqrt{\frac{1-3 x}{1+4 x}}=1-\frac{7 x}{2}
$$$$
\sqrt{\frac{1-3 x}{1-4 x}}=(1-3 x)^{\frac{1}{2}}(1+4 x)^{-\frac{1}{2}}
$$$x^2$$x$$$
\begin{aligned}
&amp; =\left(1-\frac{3 x}{2}\right) \times\left(1-\frac{4 x}{2}\right) \\
&amp; =\left(1…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:34 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 and 6 Exercise 7.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-3-p5</link>
            <description>Question 5 and 6 Exercise 7.3

Solutions of Question 5 and 6 of Exercise 7.3 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$x$$x^2$$x$$$
\frac{(8+3 x)^{\frac{2}{3}}}{(2+3 x) \sqrt{4-5 x}}=1-\frac{5 x}{8}
$$$$
\frac{\sqrt[4]{3}-3 x j^{\frac{2}{3}}}{2 \cdot 3 x+4-5 x}
$$$$
\begin{aligned}
&amp; =\frac{8^{\frac{2}{3}}\left(1+\frac{3 x}{8}\right)^{\frac{2}{3}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:34 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 and 8 Exercise 7.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-3-p6</link>
            <description>Question 7 and 8 Exercise 7.3

Solutions of Question 7 and 8 of Exercise 7.3 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$x^4$$(1-x)^{\frac{1}{4}}+(1-x)^{\frac{1}{4}}=a-b x^2$$a$$b$$$
\begin{aligned}
&amp; (1+x)^{\frac{1}{4}}+(1-x)^{\frac{1}{4}} \\
&amp; =\left[1+\frac{x}{4}+\frac{\frac{1}{4}\left(\frac{1}{4}-1\right)}{2 !} x^2+\right. \\
&amp; \left.\frac{\fra…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:35 +0000</pubDate>
        </item>
        <item>
            <title>Question 9 Exercise 7.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-3-p7</link>
            <description>Question 9 Exercise 7.3

Solutions of Question 9 of Exercise 7.3 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$x^{\prime \prime}$$\left(\frac{1+x}{1-x}\right)^2$$$
\begin{aligned}
&amp; \left(\frac{1+x}{1-x}\right)^2=(1+x)^2(1-x)^{-2} \\
&amp; =\left(x^2+2 x+1\right)(1-x)^2
\end{aligned}
$$$$
\begin{aligned}
&amp; =\left(x^2+2 x+1\right)[1+2 x+ \\
&amp; \frac{-2(-2-…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:36 +0000</pubDate>
        </item>
        <item>
            <title>Question 10 Exercise 7.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-3-p8</link>
            <description>Question 10 Exercise 7.3

Solutions of Question 10 of Exercise 7.3 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$1-\frac{1}{2^2}+\frac{1.3}{2 !} \cdot \frac{1}{2^4}+\ldots$$(1+x)^n$$$
\begin{aligned}
&amp; 1+n x+\frac{n(n-1)}{2 !} x^2 \\
&amp; +\frac{n(n-1(n-2))}{3 !} x^3+\ldots
\end{aligned}
$$$n x=-\frac{1}{4}$$\frac{n(n-1)}{2 !} x^2=\frac{1.3}{2 !} \cdot …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:37 +0000</pubDate>
        </item>
        <item>
            <title>Question 11 Exercise 7.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-3-p9</link>
            <description>Question 11 Exercise 7.3

Solutions of Question 11 of Exercise 7.3 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$y=\frac{1}{2^2}+\frac{1.3}{2 !} \cdot \frac{1}{2^4}+\frac{1 \cdot 3 \cdot 5}{3 !} \cdot \frac{1}{2^6}+\ldots$$y^2+2 y-1=0$$y=\frac{1}{2^2}+\frac{1.3}{2 !} \cdot \frac{1}{2^4}+\frac{1.3 \cdot 5}{3 !} \cdot \frac{1}{2^6}+\ldots$$$
S=y+1=1+\f…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:38 +0000</pubDate>
        </item>
        <item>
            <title>Question 12 Exercise 7.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-3-p10</link>
            <description>Question 12 Exercise 7.3

Solutions of Question 12 of Exercise 7.3 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$2 y=\frac{1}{2^2}+\frac{1.3}{2 !} \cdot \frac{1}{2^4}+\frac{1.3 \cdot 5}{3 !} \cdot \frac{1}{2^6}+\ldots$$4 y^2+4 y-1=0$$$
2 y=\frac{1}{2^2}+\frac{1.3}{2 !} \cdot \frac{1}{2^4}-\frac{1.3 \cdot 5}{3 !} \cdot \frac{1}{2^6}+\ldots
$$$S=2 y+1=…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:30 +0000</pubDate>
        </item>
        <item>
            <title>Question 13 Exercise 7.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-3-p11</link>
            <description>Question 13 Exercise 7.3

Solutions of Question 13 of Exercise 7.3 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$x$$x^3$$x$$n^{\text {th }}$$1+x$$\frac{2 n+(n+1) x}{2 n+(n-1) x}$$$
\begin{aligned}
&amp; (1+x)^{\frac{1}{n}}=\frac{2 n+(n+1) x}{2 n+(n-1) x} \\
&amp; \frac{2 n+(n+1) x}{2 n+(n-1) x} \\
&amp; =1+\frac{1}{n} x+\frac{\frac{1}{n}\left(\frac{1}{n}-1\right…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:31 +0000</pubDate>
        </item>
        <item>
            <title>Question 14 Exercise 7.3</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/ex7-3-p12</link>
            <description>Question 14 Exercise 7.3

Solutions of Question 14 of Exercise 7.3 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$x$$p x^p-q x^q=(p-q) x^{p+q}$$x$$x=1+h$$h \longrightarrow 0$$$
p x^p-q x^q=p(1+h)^p-q(1+h)^q
$$$$
\begin{aligned}
&amp; p x^p-q x^q \\
&amp; =p(1+p h+\text { higher powers h) } \\
&amp; -q(1+q h+\text { higher powcrs } h) \\
&amp; \Rightarrow p x^p-q x^q=…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:31 +0000</pubDate>
        </item>
        <item>
            <title>Question 1 Review Exercise 7</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/re-ex7-p1</link>
            <description>Question 1 Review Exercise 7

Solutions of Question 1 of Review Exercise 7 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.
Chose the correct option.$O, P, Q, R, S, T, U$$2520$$9040$$5140$$4880$$2520$$\{1,2,3,4,5,6,7\}$$14$$42$$28$$21$$28$$\{1,2,3,4,6,7,8\}$$3$$7$$120$$180$$144$$96$$120$$\dfrac{(n+2) !(n-2) !}{(n+1) !(n-1) !}$$(n-3)$$(\dot{n}-1)$$\dfrac…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:38 +0000</pubDate>
        </item>
        <item>
            <title>Question 2 Review Exercise 7</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/re-ex7-p2</link>
            <description>Question 2 Review Exercise 7

Solutions of Question 2 of Review Exercise 7 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$\left(2 x^3+3 y\right)^8$$a=2 x^3$$b=3 y$$n=8$$n=8$$\frac{8+2}{2}=5$$$
\begin{aligned}
&amp; T_5=\frac{8 !}{(8-4) ! 4 !}\left(2 x^3\right)^{8-4}(3 y)^4 \\
&amp; T_5=70.2^4 \cdot 3^4 \cdot x^{12} \cdot y^4 \\
&amp; =90720 x^{12} y^4
\end{aligne…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:40 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 &amp; 4 Review Exercise 7</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/re-ex7-p3</link>
            <description>Question 3 &amp; 4 Review Exercise 7

Solutions of Question 3 &amp; 4 of Review Exercise 7 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$(2 x-4 y)^7$$n=7, a=2 x$$b=-4 y$$$
\begin{aligned}
&amp; T_{3+1}=\frac{7 !}{(7-3) ! 3 !}(2 x)^{7 \cdot 3}(-4 y)^3 \\
&amp; =\frac{7 !}{(7-3) ! 3 !} \cdot\left(2^4\right) \cdot(-4)^3 \cdot x^4 y^3 \\
&amp; \Rightarrow T_4=-35840 x^4 y^3…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:40 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 &amp; 6 Review Exercise 7</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/re-ex7-p4</link>
            <description>Question 5 &amp; 6 Review Exercise 7

Solutions of Question 5 &amp; 6 of Review Exercise 7 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$\left(\frac{2}{x^2}+\frac{x^2}{2}\right)^{10}$$n=10, a^{\prime}=\frac{2}{x^2}$$b=\frac{x^2}{2}$$T_{r+1}$$x$$$
\begin{aligned}
&amp; T_{r+1}=\frac{10 !}{(10-r) ! r !}\left(\frac{2}{x^2}\right)^{10 r}\left(\frac{x^2}{2}\right)^r …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:41 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 &amp; 8 Review Exercise 7</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/re-ex7-p5</link>
            <description>Question 7 &amp; 8 Review Exercise 7

Solutions of Question 7 &amp; 8 of Review Exercise 7 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.$7^n-3^n$$n=1$$7^k-3^k=7-4=4$$n=1$$n=k&gt;1$$7^n-3^n=4 Q$$Q$$n=k+1$$$
\begin{aligned}
&amp; 7^{k+1}-3^{k+1}=7.7^k-3.3^k \\
&amp; =(4+3) \cdot 7^k-3.3^k \\
&amp; =4.7^k+3.7^k-3.3^k
\end{aligned}
$$$$
\begin{aligned}
&amp; =4.7^k+3\left[7^k-3^k\…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:41 +0000</pubDate>
        </item>
        <item>
            <title>Question 9 and 10 Review Exercise 7</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/re-ex7-p6</link>
            <description>Question 9 and 10 Review Exercise 7

Solutions of Question 9 and 10 of Review Exercise 7 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:43 +0000</pubDate>
        </item>
        <item>
            <title>Question 11 Review Exercise 7</title>
            <link>https://www.mathcity.org/math-11-kpk/sol/unit07/re-ex7-p7</link>
            <description>Question 11 Review Exercise 7

Solutions of Question 11 of Review Exercise 7 of Unit 07: Permutation, Combination and Probablity. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 01 Feb 2024 02:36:43 +0000</pubDate>
        </item>
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