Find the sum of first 51 terms of an AP whose second and third terms are 14 and 18 respectively.

Find the sum of first n terms of an A.P. whose nth term is 3n+1.

Find the sum of first 22 terms of an AP in which d=7 and 22nd term is 149.

Find the sum of 40 terms of an A.P. whose third term is 1 and 6th term is - 11.

Find the sum of 32 terms of an A.P. whose third term is 1 and the 6th term is -11.

Find the sum of the first a terms of the series whose nth term is: n(n + 3) .

Find the sum of the first a terms of the series whose nth term is: 3n^2+5 .

Find the sum of the first 22 terms of the AP: 8, 3, -2, ………

How many terms are there in A.P. whose first and fifth terms are -14 and 2 respectively and the sum of terms is 40 ?

If the sum of the first 14 terms of an AP is 1050 and its first term is 10, find the 20th term.