Merging man & maths https://www.mathcity.org/ Thu, 04 Jun 2026 22:36:55 +0000 FeedCreator 1.8 https://www.mathcity.org/_media/logo.svg https://www.mathcity.org/ https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-3 Exercise 6.3 (Solutions) The solutions of the Exercise 6.3 of book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan are given on this page. This exercise consists of the question related to factorial function.$n \in \mathbb{N}$${ }^{n} C_{r}=\frac{n!}{r!(n-r)!}$$n,{ }^{n-1} C_{r-1}=(n-r+1){ }^{n} C_{r-1}$$r^{n} C_{r}=(n-r+1)^{n} C_{r-1}$${ }^{n-1} C_{r-1}+{ }^{n-1} C_{r}={ }^{n} C_{r}$${ }^{n} C_{r}+{ }^{n} C… anonymous@undisclosed.example.com (Anonymous) Sat, 08 Mar 2025 09:00:35 +0000 https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-3-p10 Question 13 and 14, Exercise 6.3 Solutions of Question 13 and 14 of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $6$$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$… anonymous@undisclosed.example.com (Anonymous) Sat, 08 Mar 2025 09:00:22 +0000 https://www.mathcity.org/math-11-nbf/sol/unit06/re-ex6-p1 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,… anonymous@undisclosed.example.com (Anonymous) Sat, 08 Mar 2025 09:00:36 +0000