The density of a fish tank is 0.3fish over feet cubed. there are 15 fish in the tank. what is the volume of the tank?

5 ft3

45 ft3

50 ft3

90 ft3

The population density (d) of the fish in the tank is the number of fishes (n) in a given volume (v) 
                                        d = n / v
The volume is the quotient when n is divided by d. Substituting the known values,
                                 v = n / d  = 15 fish / 0.3 fish over ft³
Thus, the volume of the tank is 50 ft³.