Determine the sum of first thirty five terms of an arithematic progression if `t_(2)=2` and `t_(7)=22`.

Let V_(r ) denotes the sum of the first r terms of an arithmetic progression whose first term is r and the common difference is (2r-1) . Let T_(r )=V_(r+1)-V_(r)-2" and " Q_(r )=T_(r+1)-T_(r )" for " r=1,2,"...." The sum V1​+V2​+...+Vn​ is

Let V_r denote the sum of the first r terms of an arithmetic progression (AP) whose first term is r and the common difference is (2r-1). Let T_r=V_(r+1)-V_r-2 and Q_r =T_(r+1)-T_r for r=1,2... T_r is always (A) an odd number (B) an even number (C) a prime number (D) a composite num,ber

If the sum of the first two terms and the sum of the first four terms of a geometric progression with positive common ratio are 8 and 80 respectively then what is the 6th term ?

Find the sum of the first 22 terms of the AP: 8, 3, -2, ………

Find the sum of first 22 terms of an AP in which d=7 and 22nd term is 149.

Find the sum of the first a terms of the series whose nth term is: 3n^2+5 .

Find the sum of first 24 terms of the list of numbers whose nth term is given by 2n-1?

Find the sum to indicated number of terms of the geometric progressions given below:- 1,-a, a^2,-a^3 , ... n terms (if a ne -1 ).

Find the sums of the indicated number of terms of the following geometric progressions : 2,-1/2,1/8 , ........., n terms, 12 terms.