If 2n C3 : nC 2 = 12 : 1, then the value of n is ?

Explanation

Given: If 2n C3 : nC 2 = 12 : 1 Formula used : nC r = n!/r!(n - r)! Calculation: If 2n C3 : nC 2 = 12 : 1 ----(1) Using the formula 2n C 2 = {2n!/3! (2n - 3)!} ⇒ 2n(2n - 1)(2n - 2)(2n - 3)!/(2n - 3)! × 3 × 2 ⇒ n(2n - 1)2(n - 1)/3 ----(2) nC 2 = {n!/2! (n - 2)! ⇒ n(n - 1)(n - 2)!/(n - 2)! × 2 ⇒ n(n -