Each fish needs 1512 cubic inches to live. Since there are 13 fish, to find the minimum volume of the tank, we multiply 1512 by 13:
We need a rectangular solid with a volume of at least 19,656 cubic inches.
The information we have about the tank is that the length of the base is:
The width of the base is:
A representation of the situation is shown in the following diagram:
We need to find the height h of the tank.
For that, we use the formula for the volume of a rectangular solid:
In this case, the volume has to be at least 19,656 cubic inches, the length is 39 in, the width is 12in, and the height is h:
We can solve the multiplication 39x12:
And then divide both sides by 468 in order to solve for h:
Solving the division:
The minimum height of the tank has to be 42 inches.
Answer: 42 inches