The figure shows a gas tank in the form of a rectangular prism that is 40% full. How many more gallons of gas will it take to fill the tank? (1 gallon = 231 in.3)
The problem statement suggests you should convert dimensions to inches to work this problem. .. 2.75 ft = 33 in .. 1.5 ft = 18 in The empty height is .. 0.6*7 in = 4.2 in so the empty volume is .. V = (33 in)*(18 in)*(4.2 in) = 2494.8 in³
Multiplying this by the conversion factor to gallons gives .. V = (2494.8 in)³ × (1 gal)/(231 in³) = 10.8 gal
It will take 10.8 gallons of gas to fill the tank.