In the binomial expansion of `(a+b)^(n)`, the coefficients of the `4^(th)and13^(th)` terms are equal to each other, find n.

In the binomial expansion of (a - b)^(n) , n gt= 5 , the sum of 5^(th) and 6^(th) term a/b equals

In the binomial coefficients of (1 + x)^(n) , the coefficients of the 5th, 6th and 7th terms are in AP Find all values of n.

If in the expansion of (a-2b)^(n) , the sum of 5^(th) and 6^(th) terms is 0, then th e values of a//b =

(i) What is the second term in the expansion of (1 + x)^(n) ? (ii) Write the 3^(rd) and 4^(th) terms in the expansion of (1 + x)^(n) . (iii) If the coefficients of 2^(nd) , 3^(rd) and 4^(th) terms in the expansion of (1 + x)^(n) are in A.P, then show that n^(2) - 9n + 14 = 0 .

If the coefficient of 4th term in the expansion of (a+b)^n is 56, then n is

If the coefficients of (r-5)^th and (2r - 1)^th terms in the expansion of (1 + x)^34 are equal, find r.