If the sum of the coefficients of all even powers of x in the product (1+x+x^2+ +x^ 2n )(1-x+x^2-x^3+ +x^ 2n...

Question

If the sum of the coefficients of all even powers of x in the product (1+x+x^2+ +x^ 2n )(1-x+x^2-x^3+ +x^ 2n ) is 61, then n is equal to

Accepted Answer

30

JEE Main 2020 Mathematics question