Sum of first four terms of GP is `65/12` , sum of their reciprocals is `65/18` .Product of their first 3 terms is 1 and if 3rd term is `alpha` then find `2alpha`

The sum of first three terms of a G.P. is 15 and sum of next three terms is 120. Find the sum of first n terms.

The sum of first two terms of a G.P. is 5/3 and the sum to infinity of the series is 3. Find the first term :

The sum of the first four terms of an A.P.is 56 The sum of the last four terms is 112. If its first term is 11, then find the number of terms.

The sum of the first four terms of an A.P.is 56 The sum of the last four terms is 112. If its first term is 11, then find the number of terms.

The sum of first three terms of a G.P.is 13/12 and their product is -1. Find the G.P.

If sum of first 6 terms of an AP is 36 and that of the first 16 terms is 256 , then find the sum of first 10 terms.

In a geometric progression the ratio of the sum of the first 5 terms to the sum of their reciprocals is 49 and sum of the first and the third term is 35. The fifth term of the G.P. is

The sum of the first four terms of a geometric series is 520. The sum of the first five terms is 844. The sum of the first six terms is 1330. (a) Find the common ratio of the geometric progression.(b) Find the sum of the first two terms.