If ${\;^{2n + 1}}{P_{n - 1}}:{\;^{2n - 1}}{P_n}:3:5$, then the value of $n$ is equal to

JEE MATHEMATICS MCQ: PERMUTATIONS

1 Easy

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{\;^{2n + 1}}{P_{n - 1}}:{\;^{2n - 1}}{P_n}:3:5

, then the value of

n

is equal to

View answer and explanation

Correct option: A

The value of n is 4 (Option A). This is found by setting up the ratio of permutations, simplifying the equation, and solving the resulting quadratic equation for n.

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