The sum of the first and fifth terms of an AP is 26 and the product of the second and fourth is 160. Then the sum of the first six terms of the progression is

In an increasing geometric series, the sum of the first and the sixth term is 66 and the product of the second and fifth term is 128 . Then the sum of the first 6 terms of the series is:

If the sum of the first four terms of an AP is 40 and the sum of the first fourteen terms of an AP is 280. Find the sum of first n terms of the A.P.

The sum of the first three terms of an arithmetic progression is 9 and the sum of their squares is 35. The sum of the first n terms of the series can be

The sum of the third and the seventh terms of an A.P. is 6 and the product is 8. Find the sum of first sixteen terms of the A.P

The sum of the third and the seventh terms of an AP is 6 and their product is 8. Find the sum of first sixteen terms of the AP.

The sum of the first three terms of an A.P. is 9 and the sum of their squares is 35. The sum to first n terms of the series can be

The sum of the first five terms of an A.P. and the sum of the first seven terms of the same A.P. is 167. If the sum of first 10 terms of this A.P. is 235, find the sum of its first twenty terms.