English

If Nc12 = Nc8 , Then N = (A) 20 (B) 12 (C) 6 (D) 30

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Question

If nC12 = nC8 , then n =

Options

  • 20

  • 12

  • 6

  • 30

MCQ
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Solution

20

\[n = 12 + 8 = 20\]  [∵ \[{}^n C_x =^n C_y \Rightarrow n = x + y or x = y\]]
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Chapter 17: Combinations - Exercise 17.5 [Page 25]

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R.D. Sharma Mathematics [English] Class 11
Chapter 17 Combinations
Exercise 17.5 | Q 7 | Page 25

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