As the title says, you have 15 boxes, a real number is in each, and they're ordered such that box 1 contains the lowest value, box 2 the second lowest, box 3 third lowest and so on, until box 15, which contains the highest value.
You want to be sure to pick the 5 boxes with the greatest total product, such that $$\text{box} * \text{box} * \text{box} * \text{box} * \text{box} = \text{maximum amount}$$ and you want to do this with as few operations and comparison as possible. An operation is anything like $x * x$ or $x - y$, and a comparison is anything like $a > b$. What do you do?
You want to be able to know that, no matter what set of 15 in-order (least-greatest) boxes you are given, you can follow this simple formula (whatever you come up with) to always come out with the greatest product of 5 of them. And you want to come out with the minimum total of operations + comparisons that will let you always do that.
And numbers are not necessarily distinct! And all 4 of the basic operators ($+, -, *, /$) are allowed, though I am pretty sure you will only need $*$ ;)