The sum of the series `2, 5, 8, 11, ……` is `60100`, then `n` is

The A.M. of the series 1, 2, 4, 8, 16,.....,2^n is -

If the sum of the series sum_(n=0)^oor^n ,|r|<1 is s , then find the sum of the series sum_(n=0)^oor^(2n) .

If the sum of the first 2n terms of the A.P. 2, 5, 8, ..., is equal to the sum of the first n terms of A.P. 57, 59, 61, ..., then n equals

The sum to n terms of the sequence 5, 11, 17, 23, ….. is 320 Then n = .

Let a+a r_1+a r1 2++ooa n da+a r_2+a r2 2++oo be two infinite series of positive numbers with the same first term. The sum of the first series is r_1 and the sum of the second series r_2dot Then the value of (r_1+r_2) is ________.

If the sum of the series Sigma_(n=0)^(oo) r^(n),|r|le 1 is s, then find the sum of the series Sigma_(n=0)^(oo) r^(2n),|r|le 1

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 the first n terms of a series be 5n^(2) + 2n , then its second term is

If n arithmetic means are inserted between 2 and 38, then the sum of the resulting series is obtained as 200. Then find the value of ndot

The sum of the series 1^(2) + 3^(2) + 5^(2) + ......+n'