Two integers, a and b have a product of 15. what is the least possible sum of a and b?

If they're integers, that means they can't be fractions (such as 15/2 and 2).

So the only couples of integers that, when multiplied, result in 15 are:

1 and 15

5 and 3.

(there are no other possibilities as both 5 and 3 are not divisible further).

The smaller of the two sums (15+1; 5+3) is 5+3=8.

The least possible sum of a and b is 8.