JEE Main 2022 · MathsNumerical answerNumerical valueMediumCalculation

JEE Main 29 June 2022, Shift 2, Maths Q27

Question 27 of 90 in this shift, Maths question 27 of 30, Section B.

Let the coefficients of

x^{-1}

and

x^{-3}

in the expansion of

\left(2x^{\frac{1}{5}} - \frac{1}{x^{\frac{1}{5}}}\right)^{15}

x > 0

, be

m

and

n

respectively. If

r

is a positive integer such that

mn^2 = {}^{15}C_r \cdot 2^r

, then the value of

r

is equal to ___.

Official answer

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