In the `A.P.` nth term of an `A.P.` is given by `(-4n + 15).` Find the sum of first `20` terms of `A.P.`

Find the sum of first 10 terms of the A.P. 4+6+8+………

If the n^(t h) term of an A.P. is (2n+1), find the sum of first n terms of the A.P.

The nth term of an A.P. is (5n-1). Find the sum of its 'n' terms.

Find the sum of 20 terms of the A.P. 1,4,7,10…..

The sum oif the first ten terms of an A.P. is equal to 155, and the sum of the first two terms of a G.P. is 9. Find these progressionsif the first term of the A.P. equals the common ratio of the G.P. and the 1st term of G.P. equals the common difference of A.P.

If the pth term of an A.P. is (2p+3), find the A.P.

If the 8th term of an A.P. is 37 and the 15th term is 15 more than the 12th find the A.P. Also find the sum of first 20 terms of this A.P.

Find the A.P. whose nth term is 2n-3.