MathDB

The terms of an arithmetic sequence add to

715

. The first term of the sequence is increased by

1

, the second term is increased by

3

, the third term is increased by

5

, and in general, the

k

th term is increased by the

k

th odd positive integer. The terms of the new sequence add to

836

. Find the sum of the first, last, and middle terms of the original sequence.

Problem Statement