If `S_n` denote the sum of first `n` terms of an A.P. whose first term is `aa n dS_(n x)//S_x` is independent of `x ,t h e nS_p=` `p^3` b. `p^2a` c. `p a^2` d. `a^3`

Find the sum of first 31 terms of an A.P. whose nth term is (3+(2n)/(3)) .

Find the sum of the first 25 terms of an A.P. whose nth term is given by a_(n)=2-3n

Find the sum of the first 25 terms of an A.P. whose nth term is given by a_(n)=7-3n

Find the sum of first n term of the A.P., whose nth term is given by (2n+1).

Sum of first n terms of an A.P. whose last term is l and common difference is d, is

If the sum of first n terms of an A.P. is 3n^(2)-2n , then its 19th term is

Find the rth term of an A.P.the sum of whose first n terms is 3n^(2)+4n

Let S_(n) denote the sum of first n terms of an A.P.If S_(2n)=3S_(n), then find the ratio S_(3n)/S_(n)

If S_n denote the sum of n terms of an A.P. with first term a and common difference d such that (S_x)/(S_(k x)) is independent of x , then d=a (b) d=2a (c) a=2d (d) d=-a