Step-by-step explanation:

I got C. 92.08
I'm not 100% sure I did this right, but I took the money gained between years nine and eleven and divided it by 2. I tried a few other ways, but none of my answers were choices.
It is true, how??Here is explanation:
Consider a quadrilateral ABCD .Join diagnol AC so two triangles ABC & ACD will form.
Sum of interior angles of ABC is 180 and that of ACD is 180 as well.So, the total sum of the interior angles of ABC & ACD is 360 which is the sum of interior angles of quadrilateral itself.
Equation for this problem: Total 3 cubed / (L x W)
So 18.5cm x 15cm = 277.5 is the product of L and W. Now you need to devide the total by 277.5 which is 14. So the aquarium is 14 cm deep.