If nP4 = 12(nP2), find n. – InterviewSolution

InterviewSolution

1.

If nP4 = 12(nP2), find n.

Answer»

Given that ⁿP₄ = 12(ⁿP₂)

n(n – 1) (n – 2) (n – 3) = 12n(n – 1)

Cancelling n(n – 1) on both sides we get

(n – 2) (n – 3) = 4 x 3

We have product of consecutive number on both sides with decreasing order.

n – 2 = 4

∴ n = 6

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