Loading [MathJax]/jax/output/HTML-CSS/jax.js
Home / Aptitude Tests / Mathematics / If \(^{n}P_{3} - 6(^...

If nP36(nC4)=0, find the value of n....

If nP36(nC4)=0, find the value of n.

A.

5

B.

6

C.

7

D.

8

Correct answer is C

nP36(nC4)=0n!(n3)!6(n!(n4)!4!)=0n!(n3)!=6(n!(n4)!4!)n!((n4)!4!)=6n!(n3)!((n4)!4!)=6(n3)!(n4)!(n3)!=64!(n4)!(n3)(n4)!=64×3×2×11(n3)=]14n3=4n=4+3n=7