Find an A.P. whose fourth term is 9 and the sum of its sixth term and thirteenth term is 40.

Find an AP whose 4th term is 9 and the sum of its 6th and 13th terms is 40.

Find the 20th term of an A.P. whose 5th term is 15 and the sum of its 3rd and 8th terms is 34.

Find the common difference of an A.P. whose first term is 5 and the sum of its first four terms is half the sum of the next four terms.

Find the common difference of an A.P. whose first term is 5 and the sum of its first four terms is half the sum of the next four terms.

Find the common difference of an A.P. whose first term is 5 and the sum of its first four terms is half the sum of the next four terms.

Find the common difference of an A.P. whose first term is 100 and the sum of whose first six terms is five times the sum of the next six terms.

The seventh term of an AP,whose fourth term is 12 more than its first term and sum of its third and fourth term is 5 more than 3 xx its first term,is

The first term of an A.P. is 5, the last term is 45 and the sum of its terms is 1000. Find the number of terms and the common difference of the A.P.

In an A.P., the third term is p and the fourth term is q, find the 10th term and the general term.

In an A.P. whose first term is 2,the sum of first five terms in one fourth the sum of the next five terms. Show that T_(20)=-112 . Also, find S_20 .