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AP EAMCET20225 Jul 2022Evening ShiftMathematicsBinomial TheoremActual

If ^ 2 n C₃: ^ n C₃=12: 1 , then n =

Options

  1. A5
  2. B8
  3. C10
  4. D3

Correct answer

A. 5

Step-by-step solution

^ 2 n C₃ ^n C₃ = 12 1 2 n ! 3 !(2 n-3) ! n ! 3 !(n-3) ! = 12 1 aligned & 2 n(2 n-1)(2 n-2) n(n-1)(n-2) = 12 1 & 2 n(2 n-1) 2(n-1) n(n-1)(n-2) = 12 1 & 2 n-1 n-2 = 3 1 & 2 n-1=3 n-6 & n=5 aligned

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