To find the volume of the fish tank, we can use the density of the fish and the number of fish in the tank.
Given:
- Density of fish = 0.4 fish/ft³
- Number of fish = 12 fish
We can use the formula for density:
\[ \text{Density} = \frac{\text{Number of Fish}}{\text{Volume}} \]
Rearranging this formula to solve for volume gives:
\[ \text{Volume} = \frac{\text{Number of Fish}}{\text{Density}} \]
Substituting the values:
\[ \text{Volume} = \frac{12 \text{ fish}}{0.4 \text{ fish/ft}^3} \]
Calculating this:
\[ \text{Volume} = 30 \text{ ft}^3 \]
Therefore, the volume of the tank is 30 ft³.