If 12th term of an A.P. is -13 and the sum of the first four terms is 4, what is the sum of first 10 terms ?

If 12 th term of an A.P.is -13 and the sum of the first four terms is 4, what is the sum of first 10 terms?

The 12th term of an AP is -13 and the sum of its first four terms is 24. Find the sum of its first 10 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 12 terms of the A.P.

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.

If the first term of an A.P. is 3 and the sum of its first 25 terms is equal to the sum of its next 15 terms, then the common difference of this A.P. is:

If sum of first 6 terms of an AP is 36 and that of the first 16 terms is 256 , then find the sum of first 10 terms.

If the sum of the first 9 terms of an A.P. is 81 and that of the first 18 terms is 324, find the sum of its first n terms.

7^(th) term of an A.P. is 40. Then, the sum of first 13 terms is