If the sum of the first four terms of an AP is 40 and the sum of the first fourteen terms of an AP is 280. Find the sum of first n terms of the A.P.

The sum of the first p terms of an A.P. is q and the sum of the first q terms of the same A.P. is p. Find the sum of the first (p+q) terms of the A.P.

The sum of the first five terms of an A.P. and the sum of the first seven terms of the same A.P. is 167. If the sum of first 10 terms of this A.P. is 235, find the sum of its first twenty 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 twelfth term of an A.P. is (-13) and the sum of its first four terms is 24, find the sum of first 12 terms of the A.P.

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

7th term of an A.P. is 40. then the sum of the first 13 terms is

The sum of the first five terms of an AP and the sum of the first seven terms of the same AP is 167. If the sum first ten terms of this AP is 235, find the sum of its first twenty terms.

The sum of the first five terms of an AP and the sum of the first seven terms of the same AP is 167. If the sum first ten terms of this AP is 235, find the sum of its first twenty terms.

If 12th term of an A.P. is -13 and the sum of the first four terms is 24, what is the sum of first 10 terms ?