Find the volume of the rectangular prism by solving the equation V = 20 × 20 × 16.
V = 6,400
Now all you have to do is get 3/4 of that number. For me, it's easier to multiply decimals, so I will change 3/4 into it's decimal form, .75
V = 6,400 × .75 = 4,800.
The volume of the tank is 4,800 cm³.