Question 1(i-v), Exercise 6.3

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Question 1(i-v), Exercise 6.3 Solutions of Question 1(i-v) of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n\in N$$\quad^nC_r=\dfrac{n!}{r!(n-r)!}$$n$$r$$0

Question 1, Exercise 6.1

anonymous@undisclosed.example.com (Anonymous) — Sat, 08 Mar 2025 08:59:29 +0000

Question 1, Exercise 6.1 Solutions of Question 1 of Exercise 6.1 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $10!$\begin{align*} 10! &= 10 \times 9 \times 8 \times 7 \times 6 \times 5 \times 4 \\ &= 3628800 \end{align*}$\dfrac{12!}{7! 3! 2!}$\begin{align*} \dfrac{12!}{7! \, 3! \, 2!} &= \dfrac{12 \times 11 \times 10 \times 9 \times 8 \times 7!}{7! …

Question 2, Exercise 6.1

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Question 2, Exercise 6.1 Solutions of Question 2 of Exercise 6.1 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\quad 14\cdot 13\cdot 12\cdot 11$\begin{align*} &14\cdot 13\cdot 12\cdot 11\\ = & \dfrac{14\cdot 13\cdot 12\cdot 11\cdot 10!}{10!} \\ = & \dfrac{14!}{10!} \end{align*}$\quad 1\cdot 3\cdot 5 \cdot 7 \cdot 9$$$1 \times 3\times 5\times 7 \time…

Question 3 and 4, Exercise 6.1

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Question 3 and 4, Exercise 6.1 Solutions of Question 3 and 4 of Exercise 6.1 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\quad \dfrac{1}{5!}+\dfrac{3}{6!}+\dfrac{1}{7!}=\dfrac{4}{315}$\begin{align*} LHS = & \dfrac{1}{5!}+\dfrac{3}{6!}+\dfrac{1}{7!} \\ = & \dfrac{1}{5!}+\dfrac{3}{6\cdot 5!}+\dfrac{1}{7\cdot 6\cdot 5!}\\ = & \dfrac{1}{5!}\left(1+\dfr…

Question 5, Exercise 6.1

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Question 5, Exercise 6.1 Solutions of Question 5 of Exercise 6.1 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$\quad \dfrac{n}{(n-4)!}=\dfrac{3.3!}{(n-3)!}$\begin{align*} \dfrac{n}{(n-4)!}&=\dfrac{3.3!}{(n-3)!}\\ \dfrac{n}{(n-4)!}&=\dfrac{3.3!}{(n-3)(n-4)!}\\ n&=\dfrac{3\times 6}{n-3}\\ n(n-3)&=18\\ n^2-3n&=18\\ n^2-2n-18&=0\\ n^2+3n-6n-18&=0\\ n(…

Question 6(i-v), Exercise 6.1

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Question 6(i-v), Exercise 6.1 Solutions of Question 6(i-v) of Exercise 6.1 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n\in N$$\quad (2n)!=2^n(n!)[1\cdot3\cdot5 \cdots (2n-1)]$\begin{align*} (2n)!&= (2n)(2n-1)(2n-2)(2n-3)\cdots (2n-n)(2n-(n+1))\cdots4.3.2.1\\ &= (2n)(2n-1)(2n-2)(2n-3)\cdots (n)(n-1)\cdots4.3.2.1\\ &= (2n)(2n-1)(2n-2)(2n-3)\cdots (n…

Question 6(vi-ix), Exercise 6.1

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Question 6(vi-ix), Exercise 6.1 Solutions of Question 6(vi-ix) of Exercise 6.1 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n\in N$$\quad 33!$$2^{15}$$$33!=33.32.31\cdots4.3.2.1$$$2,4,8,16,32$$2^1,2^2,2^3,2^4,2^5$\begin{align*}33!&=2^5.2^4.2^3.2^2.2(33\times31\times\cdots6\times5\times3\times1)\\ &=2^{15}(33\times31\times\cdots\times3\times1)\end{al…

Question 7(i-vi), Exercise 6.1

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Question 7(i-vi), Exercise 6.1 Solutions of Question 7(i-vi) of Exercise 6.1 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$\quad \dfrac{n!}{(n-2)!}=930,\quad n \geq 2$\begin{align*} \dfrac{n!}{(n-2)!}&=930\\ \dfrac{n(n-1)(n-2)!}{(n-2)!}&=930\\ n(n-1)&=930\\ n^2-n-930&=0 \end{align*}\begin{align*} n&=\dfrac{1\pm \sqrt{1+4(930)}}{2}\\ &=\dfrac{1\pm …

Question 7(vii-xi), Exercise 6.1

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Question 7(vii-xi), Exercise 6.1 Solutions of Question 7(vii-xi) of Exercise 6.1 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$\quad n!=990 \cdot (n-3)!$\begin{align*} n!&=990 (n-3)!\\ n(n-1)(n-1)(n-3)!&=990 (n-3)!\\ n(n-1)(n-1)&=990 \\ n^3-3n^2+2n-990 &=0\\ \end{align*}\[\begin{array}{c|cccc} & 1 & -3 & 2 & -990 \\ 11 & 0 & 11 & 88 & 990 \\…

Question 1, Exercise 6.2

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Question 1, Exercise 6.2 Solutions of Question 1 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n \in N$$\quad^nP_r=\dfrac{n!}{(n-r)!}$$n$$r$$\dot{n}$$2^{\text {nd }}$$(n-1)$$3^{\text {rd }}$$(n-2)$$r^{\text {th }}$$(n-(r-1)$$$ { }^{n} P_{r}=n(n-1)(n-2) \ldots(n-(r-1)) $$$(n-r)(n-r-1) \ldots 3,2.1$${ }^{n} P_{r}=\frac{n(n-1)(n-2)\ldots…

Question 2, Exercise 6.2

anonymous@undisclosed.example.com (Anonymous) — Sat, 08 Mar 2025 08:59:49 +0000

Question 2, Exercise 6.2 Solutions of Question 2 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$\quad ^nP_4=20\, ^nP_2$\begin{align*} \dfrac{m}{(n-4)!}&=20 \cdot \dfrac{m}{(n-2)!}\\ \dfrac{1}{(n-4)!}&=\dfrac{20}{(n-2)(n-3)(n-4)!}\\ (n-2)(n-3)&=20\\ n^{2}-5 n+6&=20\\ n^{2}-5 n-14&=0\\ n^{2}+2 n-7 n-14&=0\\ n(n+2)-7(n+2)&=0\\ (n+2)(n-…

Question 3, Exercise 6.2

anonymous@undisclosed.example.com (Anonymous) — Sat, 08 Mar 2025 08:59:50 +0000

Question 3, Exercise 6.2 Solutions of Question 3 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $r$$^6P_{r-1}=^5P_4$\begin{align*}{ }^{6} P_{r-1}&={ }^{5} P_{4}\\ \dfrac{6!}{(6-(r-1))!}&=\dfrac{5!}{(5-4)!}\\ \dfrac{6!}{(7-r)!}&=\dfrac{5!}{1!} \\ \frac{6 \times 5!}{(7-r)!}=\dfrac{5!}{1} 6&=(7-r)!\\ 3!&=(7-r)!\\ 3&=7-r \\ r&=7-3\\ r&=4\en…

Question 4 and 5, Exercise 6.2

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Question 4 and 5, Exercise 6.2 Solutions of Question 4 and 5 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $3$$1,2,3,4,5,6,$$3$$6$$\mathrm{I}:$$2$$$\underline{ },\underline{ },\underline{2}$$$={ }^{5} P_{2}=20$$4$$$\underline{ },\underline{ },\underline{4}$$$={ }^{5} P_{2}=20$$6$$$\underline{ },\underline{ },\underline{6}$$$={ }^{5} P_…

Question 6 and 7, Exercise 6.2

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Question 6 and 7, Exercise 6.2 Solutions of Question 6 and 7 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $4$$$1,2,3,4,5,6$$6$$6$$6$$6$$$\text{Total possibilities }6 \times 6 \times 6 \times 6=6^4=1296$$$1,1,2,2,3,3,4$$=7$$2^{\text {nd }}$$6^{\text {th }}$$1^{\text {st }}, 3^{\text {rd }}, 5^{\text {th }}$$7^{\text {th }}$$2,2,4$$1,1,…

Question 8 and 9, Exercise 6.2

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Question 8 and 9, Exercise 6.2 Solutions of Question 8 and 9 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $4$$5$$5$$4$$41$$=41 \times 41=576$$2$$3$$4$$$\text{Total flags} =9$$$$\text{Repetition of blue }=2$$$$\text{Repetition of yellow}=3$$$$\text{Repetition of green}=4$$\begin{align*}\text{Total signals }&=\dfrac{9!}{2!3!4!}\\ &=\dfr…

Question 10 and 11, Exercise 6.2

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Question 10 and 11, Exercise 6.2 Solutions of Question 10 and 11 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $=6$$={ }^{6}{ }^{1} P_{5}=6$$720$$F$$F$$5$$5!=120$$=9$$S=2$$T=2$$A=2$\begin{align*}\text{possible permutation}&=\dfrac{9!}{2!2!2!}\\ &=\dfrac{362880}{8}\\ &=45360\end{align*}

Question 12 and 13, Exercise 6.2

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Question 12 and 13, Exercise 6.2 Solutions of Question 12 and 13 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $=5$$5$$=5!=120$$O$$E$$21=2$$3$$3!= 6$$O$$E$$=6 \times 2=12$$0$$E$$=120-12=108$$=7$$7$$=71=5040$$3$$A, I$$E$$3$$4$$$5!=120$$$3$$=6$$$6 \times 120=\mathbf{7 2 0}$$$5040$$720$$3$$5040-720=4320$

Question 14 and 15, Exercise 6.2

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Question 14 and 15, Exercise 6.2 Solutions of Question 14 and 15 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $3$$=7$$=3$$={ }^{7} P_{3}=\dfrac{7!}{4!}=210$$5$$3$$2$$3$$=31=6$$=(5!\times 3!\times 2!) \times 31=8640$

Question 16 and 17, Exercise 6.2

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Question 16 and 17, Exercise 6.2 Solutions of Question 16 and 17 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $1,2,3,4,5,6$$1, 3$$5$$=3 \times{ }^{5} P_{5}=360$$4$$1,2,3,4$$5$$1$$={ }^{4} P_{3}=24$$3$$24$$5$$24$$24+24+24=72$$4$

Question 18 and 19, Exercise 6.2

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Question 18 and 19, Exercise 6.2 Solutions of Question 18 and 19 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $10,000$$0,2,3,5,6$$4$$10000$$3$$5$$0$$3={ }^{3} P=6$$0$$5=3 p_{6}=6$$10000$$5$$=6+6=12$$3$$4$$5$$={ }^{4} P_{3}=2$$4$$5$$4$$5={ }^{4} P_{3}=24$$3$$3$$3$$5=$${ }^{4} P_{2}=12$$3$$5$$3$$5=$${ }^{4} P_{2}=12$$2$$3$$2$$5={ }^{4} …

Question 20 and 21, Exercise 6.2

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Question 20 and 21, Exercise 6.2 Solutions of Question 20 and 21 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $6$$6$$5!$$6$$6!$$=5! \times 6!=86400$$= n = 4$$= {}^4P_4 = 24.$

Question 22 and 23, Exercise 6.2

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Question 22 and 23, Exercise 6.2 Solutions of Question 22 and 23 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $(3\quad 4\quad 6\quad 1\quad 5\quad2)$$1$$2$$L=1, A=2, H=3, O=4, R=5, E=6$$(3,4,6,1,5,2)=$$(4\quad 6\quad 3\quad 2\quad 1\quad5)$$(4,6,3,2,1,5)$$4^{\text {th }}$$2^{\text {nd }}$$6^{\text {th }}$$3^{\text {rd }}$$3^{\text {rd…

Question 1(vi-x), Exercise 6.3

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Question 1(vi-x), Exercise 6.3 Solutions of Question 1(vi-x) of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n\in N$$\quad^{2n}C_n=\dfrac{2^n[1.3.5.\cdots(2n-1)]}{n!}$\begin{align*}L.H.S &=\quad^{2n}C_n \\ &=\dfrac{(2 n)!}{n!(2 n-n)!}\\ &=\dfrac{(2 n)(2 n-1)(2 n-2)(2 n-n)(2 n-(n+1)) ..2 .1}{n!\cdot n!}\\ &=\dfrac{(2 n)(2 n-1)(2 n-2) ..(…

Question 2, Exercise 6.3

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Question 2, Exercise 6.3 Solutions of Question 2 of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$\,\, ^nC_5=\,\, ^nC_8$\begin{align*}\dfrac{n!}{5!(n-5)!}=\dfrac{n!}{8!(n-8)!}&\\ \dfrac{1}{8!(n-5)(n-6)(n-7)(n-8)!}&\\ =\dfrac{1}{8 \times 7 \times 6 \times 8!(n-8)!}&\\ 336=(n-5)(n-6)(n-7)&\\ (n-5)\left(n^{2}-13 n+42\right)&=336\\ n^{3}-…

Question 3, Exercise 6.3

anonymous@undisclosed.example.com (Anonymous) — Sat, 08 Mar 2025 09:00:27 +0000

Question 3, Exercise 6.3 Solutions of Question 3 of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $r$$\quad^{15}C_{3r}= ^{15}C_{3+r}$$${ }^{n} C_{r}={ }^{n} C_{n-r}$$\begin{align*}n=15\quad&\text{put} \quad r=3 r\\ n-3 r&=r+3\\ 15-3 r&=r+3 \\ 15-3 & =3 r+r \\ 12 & =4 r\\ r&=3\end{align*}$r$$\quad^{8}C_{r}-\,^7C_3= ^{7}C_{2}$\begin{align*}…

Question 4, Exercise 6.3

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Question 4, Exercise 6.3 Solutions of Question 4 of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$r$$\,\,^nC_{r-1}:\,^nC_{r}:\,^nC_{r+1}=6:14:21$\begin{align*}\dfrac{n!}{(r-1)!(n-(r-1))!}&: \dfrac{n!}{r!(n-r)!}\\ : \dfrac{n!}{(r+1)!(n-(r+1))!} &= 6:14:21\\ \dfrac{1}{(r-1)!(n-r+1)!}: \dfrac{1}{r!(n-r)!}&\\ : \dfrac{1}{(r+1)!(n-r-1)!}&=…

Question 5 and 6, Exercise 6.3

anonymous@undisclosed.example.com (Anonymous) — Sat, 08 Mar 2025 09:00:29 +0000

Question 5 and 6, Exercise 6.3 Solutions of Question 5 and 6 of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $11$$16$$11$$16$${ }^{16} C_{11}$$4368$$11$$11$$16$$10$$15$$$ { }^{15} C_{10}=3003 $$$5$$3$$3$$1$${ }^{5} C_{1}$$2$${ }^{3} C_{2}$$={ }^{5} C_{1} \times{ }^{3} C_{2}=5 \times 3=15$$2$$={ }^{5} C_{2} \times{ }^{3} C_{1}=10 \times 3…

Question 7 and 8, Exercise 6.3

anonymous@undisclosed.example.com (Anonymous) — Sat, 08 Mar 2025 09:00:29 +0000

Question 7 and 8, Exercise 6.3 Solutions of Question 7 and 8 of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $5$$6$$4$$2$$2$$3$$={ }^{4} C_{2} \times{ }^{6} C_{3}=6 \times 20=120$$5$$6$$4$$2$$2$$2$$2,3$$2$$120$$3$$2$$={ }^{4} C_{3} \cdot{ }^{6} C_{2}=4 \times 15=60$$4$$={ }^{4} C_{4} \times{ }^{6} C_{1}=1 \times 6=6$$=120+60+6=186$$5$$6$…

Question 9 and 10, Exercise 6.3

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Question 9 and 10, Exercise 6.3 Solutions of Question 9 and 10 of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$n$$n$$n$$C_{2}$$n$$n$$={ }^{n} C_{2}-n$$=\frac{n!}{2!(n-2)!}-n$$10$$10$$3$$7$$10$${ }^{10} C_{7}$$7$$3$$7={ }^{10} C_{7}=120$

Question 11 and 12, Exercise 6.3

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Question 11 and 12, Exercise 6.3 Solutions of Question 11 and 12 of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$35$$n$\begin{align*}{ }^{n} C_{2}-n&=35\\ \text{or} \quad \dfrac{n!}{2!(n-2)!}-n&=35\\ \dfrac{n(n-1)(n-2)!}{2(n-2)!}-n&=35\\ \dfrac{n(n-1)-2 n}{2}&=35\\ n^{2}-n-2 n&=70\\ n^{2}-3 n-70&=0\\ n^{2}+7 n-10 n-70 & =0 \\ n(n+7)-…

Question 13 and 14, Exercise 6.3

anonymous@undisclosed.example.com (Anonymous) — Sat, 08 Mar 2025 09:00:22 +0000

Question 13 and 14, Exercise 6.3 Solutions of Question 13 and 14 of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $6$$1$$1$$2$$6$$1$$6={ }^{6} C_{1}=6$$2$$6={ }^{6} C_{2}=15$$3$$6={ }^{6} C_{3}=20$$4$$6={ }^{6} C_{4}=15$$5$$6={ }^{6} C_{5}=6$$6$$6={ }^{6} C_{6}=1$$$\text{Total}\quad =6+15+20+15+6+1=63$$$A$$B$$C$$8$$5$$A$$3$$B$$C$$5$$8$$A$…

Question 1, Review Exercise 6

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Question 1, Review Exercise 6 Solutions of Question 1 of Review Exercise 6 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $3\,\,^nP_3=^nP_4$$n$$5$$6$$7$$8$$6$$ 480$$600$$720$$840$$720$$r$$r!$$(r+1)!$$r!+1$$ 2r!$$r!$$6$$\dfrac{5}{2}\,\,6!$$6!$$\dfrac{1}{2}\,\,6!$$\dfrac{3}{2}\,\,6!$$\dfrac{5}{2}\,\,6!$$A=\{1,2,3,4,...,20\}. $$3$$5$$7$$8$$8$$A=\{1,3,5,7,…

Question 2 and 3, Review Exercise 6

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Question 2 and 3, Review Exercise 6 Solutions of Question 2 and 3 of Review Exercise 6 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $4$$26$$$^{26}P_4=358800$$$3$$0$$3$$100's$$9$$3$$$=10\times 10\times10=1000$$$0$$10$$3-$$0$$$=10\times 10=100$$

Question 4, 5 and 6, Review Exercise 6

anonymous@undisclosed.example.com (Anonymous) — Sat, 08 Mar 2025 09:00:38 +0000

Question 4, 5 and 6, Review Exercise 6 Solutions of Question 4, 5 and 6 of Review Exercise 6 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $0,2,3,4,5,7$$6$$$=6!=720$$$0$$5$$$5!=120$$$6-$$$=720-120=600$$$7$$$(7-1)!=720$$$2$$$\dfrac{720}{2}=360$$$11!$$10!$$$=11!-10!=36288000$$

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