Question

Can the sum of 'n' terms in an A.P. is n2 + 13n. Justify your answer.​

Answer 1

Yes it can be $n^{2} + 13n$.

The formula for sum of 'n' terms in an A.P. is given by :

$\frac{n}{2} (2a+(n-1)d)$

Now, assuming the answer to be true, we get the values:

a = 14, d = 2.

Hence, for an A.P starting from 14 with a difference between two terms being 2, the sum of n terms is $n^{2} + 13n$.