To determine the volume of the fish tank given the density and the number of fish, we can use the relationship between density, mass (or in this case, the number of fish), and volume. The formula for density is:
[tex]\[
\text{Density} = \frac{\text{Number of fish}}{\text{Volume}}
\][/tex]
We are given:
- The density of fish in the tank: [tex]\( 0.3 \frac{\text{fish}}{\text{feet}^3} \)[/tex]
- The number of fish in the tank: [tex]\( 15 \text{ fish} \)[/tex]
We need to find the volume of the tank ([tex]\( V \)[/tex]). Rearrange the formula to solve for volume:
[tex]\[
\text{Volume} = \frac{\text{Number of fish}}{\text{Density}}
\][/tex]
Substitute the given values into the formula:
[tex]\[
V = \frac{15 \text{ fish}}{0.3 \frac{\text{fish}}{\text{feet}^3}}
\][/tex]
Perform the division:
[tex]\[
V = \frac{15}{0.3}
\][/tex]
[tex]\[
V = 50 \text{ cubic feet}
\][/tex]
Therefore, the volume of the tank is [tex]\( 50 \text{ feet}^3 \)[/tex], which matches one of the given choices:
[tex]\[
\boxed{50 \text{ feet}^3}
\][/tex]
