Answer: There are 16 fish that he can keep in the aquarium.
Step-by-step explanation:
Since we have given that
Length of aquarium = 4 feet
Width of aquarium = 1 foot
So, it forms a shape of cuboid.
As we know the formula for "Volume of Cuboid":
[tex]Volume=Length\times Breadth\times Height\\\\Volume=4\times 1\times 2\\\\Volume=8\ ft^3[/tex]
According to question, Each fish needs atleast 0.5 cubic feet of water.
So, Number of fish that he can keep in the aquarium is given by
[tex]\frac{8}{0.5}=16[/tex]
Hence, there are 16 fish that he can keep in the aquarium.