If the sum of n terms of an A.P is cn (n-1)where `c ne 0` then the sum of the squares of these terms is

If the sum of first n terms of an A P is c n^2, then the sum of squares of these n terms is (2009)

Sum of n-terms of a G.P. is ___.

If the sum of the n terms of a G.P. is (3^(n)-1) , then find the sum of the series whose terms are reciprocal of the given G.P..

If the sum of m terms of an A.P. is same as the sum of its n terms, then the sum of its (m+n) terms is

If the nth term of an A.P. is t_(n) =3 -5n , then the sum of the first n terms is ………

If the sum of 12^(th) and 22^(nd) terms of an A.P is 100, then the sum of the first 33 terms of the A.P is

If the sum of n terms of an A.P. is 3n^(2) + 5n and its m^(th) term is 164, find the value of m .

If the sum of first 75 terms of an A.P. is 2625, then the 38^(th) term of the A.P. is

If the sum of p terms of an A.P is equal to sum of q terms (p != q) then the sum of (p + q) terms is

If the sum to first n terms of the A.P. 2, 4, 6, …. is 240, then the value of n is