Answer: 2 feets
Explanation:
Recommended density = 7 fish/ ft^3
If recommended density guideline is followed:
Number of fishes in aquarium = 42
Length of aquarium = 3ft
Width = 1ft
Height =?
Volume of aquarium = Length × width × height
Volume = 3 × 1 × h = (3ft^2 × h)
Therefore ;
If
1ft^3 = 7 fishes
x ft^3 = 42 fishes
Cross multiply
7(x)ft^3 = 42 fishes
x ft^3 = (42÷7)
x ft^3 = 6
Therefore volume of the aquarium with 42 fishes is 6ft^3
Volume = (3ft^2 × h)
6ft^3 = 3ft^2 × h
h = (6ft^3) / (3ft^2)
h = 2ft