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 term of the AP.

The sum of the 4th and 8th terms of an AP is 24 and the sum of the 6th and 10th terms is 44. Find the first three terms of the AP.

If the sum of first 7 terms of an AP is 49 and that of 17 terms is 289, find the sum of first n terms.

The first term of G.P. is 27 and 8th term is 1/81 . Find the sum of its first 10 terms.

The twelfth term of an A.P. is (-13) and the sum of its first four terms is 24, find the sum of first 10 terms of the A.P.

The fifth terms of an A.P. is 30 and its twelfth term is 65, find the sum of its first 20 terms.

The pth term of an A.P. is a and qth term is bdot Then find the sum of its (p+q) terms.

The sum of first 15 terms of an A.P. is 750 and its first term is 15. Find its 20th term.

The n term of an A.P is 7n-5,find the sum of first 20 terms of the series.

If the seventh term of an A.P. is 1/9 and its ninth term is 1/7 , find its 63rd term.

The 10th term of an A.P. is (-15) and the 31st term is (-57). Find the first term and common difference of the A.P.