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JEE MATHEMATICS MCQ: PERMUTATIONS

1 Easy

1 of 1

Understanding +4 | -1

The value of

\sum\limits_{{r=1}}^n \frac{{ }^n P_r}{r !}

is

View answer and explanation

Correct option: B

2^n-1

Option B (

2^n-1

) is correct because the given sum is equivalent to the sum of binomial coefficients from r=1 to n, which equals

2^n - 1

.

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