If the second term and the fourth terms of an A.P. are 12 and 20 respectively, then find the sum of first 25 terms:

If the third and 11th terms of an A.P. are 8 and 20 respectively, find the sum of first ten terms.

If the second and seventh terms of an A.P. are 2 and 22 respectively. Find the sum of first 35 terms:

If the 5th and 12th terms of an A.P. are 30 and 65 respectively, what is the sum of first 20 terms?

If first term, second term and last term of an A.P are a,b and 2a respectively then there sum is……

If the 5th and 12th terms of an A.P. are 30 and 65 respectively, what is the sum of the first 20 terms ?

The 1st term and the common difference of an A.P. are 10,000 and 2000 respectively . Find the sum of the first 12 terms.

The first, second and last terms of an A.P. are a, b, c respectively, then the sum to first n terms is

The fifth terms of an A.P. is 30 and its twelfth term is 65, find the sum of its first 20 terms.