If n + 2 C 6 n - 2 P 2 = 11 , then n satisfies the equation:

If n+2C6n-2P2=11, then n satisfies the equation:
  1. n2+n-110=0
  2. n2+2n-80=0
  3. n2+3n-108=0
  4. n2+5n-84=0

Solution

n+2C6n-2P2=11

⇒ n+2 n+1 n n-1 n-2 n-36 .5 . 4 . 3. 2. 1 n-2 n-3=11

⇒ n+2 n+1 nn-1=11.10.9.8

⇒ n=9

Asked in: JEE Main 2016 (10 Apr Online)

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