A basement has a 24-foot by 32-foot rectangular floor. The basement is flooded with water to a depth of 18 inches. Three pumps are used to pump the water out of the basement. Each pump will pump 8 gallons of water per minute. If a cubic foot of water contains 7.5 gallons, how many minutes will it take to pump all of the water out of the basement using the three pumps?
Note that 18 in = 1.5 ft
So....the cubic feet of water in the basement = 24 x 32 x 1.5 = 1152 ft^3
Each pump pumps out 8 gal of water / minute
So....the number of cubic feet they pump out each minute = 8 / 7.5 = 16/15 ft^3 min
So...three of them pump out 3 (16/15) = 48/15 = 16/5 ft^3 min
So.....the number of minutes to pump out the basement is 1152 / (16/5) = 1152 * 5 / 16 = 360 minutes = 6 hours