Let the coefficients of x^ -1 and x^ -3 in the expansion of (2x^ 1/5 − 1/x^ 1/5 )^ 15 , x 0, be m and n...

Question

Let the coefficients of x^ -1 and x^ -3 in the expansion of (2x^ 1/5 − 1/x^ 1/5 )^ 15 , x > 0, be m and n respectively. If r is a positive integer such that mn^ 2 = ^ 15 C_ r 2^r, then the value of r is equal to _____.

Accepted Answer

5

JEE Main 2022 Mathematics question

Solution

See the full step-by-step solution