If the sum of an A.P. is 72 whose first term is 17 and common difference is -2. Find the number of terms.

Find the nth term of AP whose first term is 12 and common difference is 7.

The sum of n terms of an A.P. whose first term is 5 and common difference is 36 is equal to the sum of 2n terms of another A.P. whose first term is 36 and common difference is 5. Find n.

Find the 12th term of AP if first term is 5 and common difference is 7.

If S_n denotes the sum of n terms of an A.P. whose first term is a, and the common difference is d Find: = Sn - 2Sn + S(n +2) .

Write first four terms of A.P. when first term a = 3 and common difference d= 2.

Write first four terms of A.P. when first term a = -2and common difference d= 0.

Find the sum of A.P first term 3 and common difference 2 and n=5

Write first four terms of A.P. when first term a = 4 and common difference d = 3.

By the Principle of Mathematical Induction, prove the following for all n in N : The nth term of an A.P. whose first term is 'a’ and common difference ‘d' is a + (n-1) d.