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Manipal MET2021MathematicsBinomial Theorem

If C(2 n, 3): C(n, 2)=44: 3 , then n is equal to

Options

  1. A6
  2. B7
  3. C5
  4. D8

Correct answer

A. 6

Step-by-step solution

Given, ^ 2 n C₃: ^n C₂= 44 3 aligned & 2 n! (2 n-3)!3! 2!(n-2)! n! = 44 3 & 2 n(2 n-1)(2 n-2) 3 1 n(n-1) = 44 3 & 2 3 2(2 n-1)= 44 3 & 2 n-1=11 2 n=12 n=6 aligned

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