Prove that a sequence in an A.P., if the sum of its `n` terms is of the form `A n^2+B n ,w h e r eA ,B` are constants.

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

The number of terms in the expansion of (a+b+c)^n ,w h e r en in Ndot

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 7^(th) term of n A.P is 40. Then the sum of its first 13 terms is

Find the sum of the first 28 terms of an A.P. whose nth term is 4n-3.

If the roots of the equation x^3+P x^2+Q x-19=0 are each one more that the roots of the equation x^3-A x^2+B x-C=0,w h e r eA ,B ,C ,P ,a n dQ are constants, then find the value of A+B+Cdot

Find the sum of the first 30 terms of an A.P. whose nth term is 3 + 2n.

Find the sum to n terms of the A.P., whose k^("th") term is 5k + 1.