The third term of an A.P. is 7 and its seventh term is 2 more than three times the third term. Find the sum of first 20 terms.

The seventh term of an A.P. is 20 and the sum of first twenty terms is 610. Find the tenth term and the sum of first fifteen terms.

The pth term of an A.P. is q and qth term is p . Show that the nth term is p+q-n .

the 6th term of an A.P. is -10 and its 10th term -26 determine the 15 term of the A.P.

The pth term of an A.P. is —q and qth term is -p. If the nth term is zero, find n.

The fifth and ninth terms of an A.P. are respectively -15 and -13. Find the sum of first ten terms.

The nth term of an A.P the sum of whose n term is S_n is____

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.

If the qth term of an A.P. is twice the pth term and rth term is twice the qth term. Prove that -2p+r=3q

If the qth term of an A.P is twice the pth term and rth term is twice the qth term. prove that 2p+r=3q

In an A.P. the ratio of 7th term to 11th term is 19 : 31 and the sum of these two terms is 20.Find the sum of first twenty terms.