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JEE MATHEMATICS MCQ: PERMUTATIONS

1 Easy

1 of 1

Application +4 | -1

Find

n

if

{ }^{n-1} P_3:{ }^n P_4=1: 9

View answer and explanation

Correct option: A

9

Option A (9) is correct because the ratio

{ }^{n-1} P_3:{ }^n P_4=1: 9

simplifies to

\frac{1}{n}=\frac{1}{9}

, which gives

n=9

.

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