Question

What is the surface area of fish tank in the shape of a cube that has a volume of 90 cubic inches.

Answer 1

You know that the volume of the fish tank in the shape of a cube:

`V=90in^3`

By definition, the formula for calculating the volume of a cube is:

`V=a^3`

Where "a" is the length of each edge of the cube.

If you solve for "a", you get this formula:

`a=\sqrt[3]{V}`

In this case, knowing the volume of the cube, you can substitute it into the second formula and evaluate, in order to find the length of each edge of the cube:

`\begin{gathered} a=\sqrt[3]{90in^3} \\ \\ a\approx4.48in \end{gathered}`

The surface area of a cube can be found using this formula:

`SA=6a^2`

Where "a" is the length of each edge of the cube.

Substituting the value of "a" into the formula and evaluating, you get:

`SA=6(4.48in)^2\approx120in^2`

Hence, the answer is: Second option.