If three successive coefficients in the expansion of `(1+x)^n` are 220, 495 and 792, then find n.

If three successive coefficients in the expansion of (1+x)^n are 28, 56 and 70, find n.

If the three consecutive coefficients in the expansion of (1 + x)^n are in the ratio 1: 3 : 5, then the value of n is:

The coefficient of x^(n) in the expansion of (1+x)(1-x)^(n) is

Find the coefficient of x^8 in the expansion of (x^2-1/x)^(10)

Find the coefficient of x^5 in the expansion of (x+3)^6 is :

The middle term in the expansion of (1 + x)^(2n) is :

Find the coefficient of x^n in the expansion of: (a+bx+cx^2)/e^x .

If the coefficients of 5th, 6th , and 7th terms in the expansion of (1+x)^n are in A.P., then n=