JEE Main 20207 Jan, Morning shiftMathematicsMediumBinomial Theorem and Its Simple Applications131× since 2002
If the sum of the coefficients of all even powers of x in the product
(1 + x + x²
+ ....+ x2n)(1 - x + x² - x³ + ...... + x2n) is 61, then n is equal to _______.