The coefficients of three consecutive terms in the expansion of `(1 + a)^n` are are in the ratio 1: 7: 42 Find n.

The coefficients of the middle term in the expansion of (1+x)^(40) is

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

The coeffcients of the (r-1)^th , r^th and (r+1)^th terms in the expansion of (x+1)^n are in the ration 1 : 3: 5 Find n and r.

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

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

If the coefficients of r^(th) and (r+1)^(th) term in the expansion of (1+x)^(n) are equal then n=

If the coefficient of the r^(th) term and the (r+1)^ (th) term is the expansion of (1+x)^(20) are in the ratio 1: 2 then r =

The greatest coefficient in the expansion of (1+x)^(2n) is

If the coefficients of second, third and fourth terms in the expansion of (1+x)^(2 n) are in A.P, then,

The number of terms in the expansion of (a+b+c)^(n), where n in N is: