Find the S_nfor the following arithmetic series described.

(i) a = 5, n = 30, l = 121 (ii) a = 50, n = 25, d = – 4

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

Find the sum of each arithmetic series

Find the sum of the first 40 terms of the series 1² – 2² + 3² – 4² + … .

In an arithmetic series, the sum of first 11 terms is 44 and that of the next 11 terms is 55. Find the arithmetic series.