Question

If ^nP3 = 4*^nP2. Find n.

(a) 3

(b) 2

(c) 6

(d) 5

The question was posed to me by my college director while I was bunking the class.

I want to ask this question from Permutations-2 topic in section Permutations and Combinations of Mathematics – Class 11

Answer 1

Right option is (c) 6

Explanation: ^nP3 = 4*^nP2

\(\frac{n!}{(n-3)!} = 4 * \frac{n!}{(n-2)!}\)

=> n-2 = 4

=> n=6.