Q4 of 202 Page 10

The first and last terms of an A.P. are 1 and 11. If the sum of its terms is 36, then the number of terms will be

a₁ = 1 (first term)

a₁₁ = 11 = l (last term)

S_n= 36

But, S_n = (a + l)

36= (12)

n= 6

If the sum of P terms of an A.P. is q and the sum of q terms is p, then the sum of p + q terms will be

If the sum of n terms of an A.P. be 3n² + n and its common difference is 6, then its first term is

If the sum of n terms of an A.P. is 3n² + 5n then which of its terms is 164?

If the sum of n terms of an A.P. is 2n² + 5n, then its nth term is