Question

The sum of the first n terms (n > 1) of an ap is 153

Answer 1

49+51+53 = 153

My answer is not wrong, yours is.Enough said.

Sum of A.P = n(n-1)/2 x r + an

=n(n-1) + an

For 3:

153-3² +3 is divisible by 3

hence,the first term is an integer.

Therefore, it is possible that n is 3.

For 4:

153-4²+4 is not divisible by 4,therefore first term is not an integer.

For 5:

153-5²+5 is not divisible by 5,therefore first term is not an integer.

For 6:

153-6²+6 is not divisible by 6,therefore first term is not an integer