jmc

Question

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?

Accepted Answer

The height of the water initially in feet is (18 inches)/(12 inches/foot)=1.5 feet. The amount of water in the basement initially is 1.52432=1152 cubic feet. Converting this to gallons, we have (1152 ft^3)(7.5 gallons/ft^3)=8640 gallons. If each pump can pump out 8 gallons of water per minute, then three pumps can pump out 83=24 gallons a minute. So it will take (8640 gallons)/(24 gallons/minute)=360 minutes to pump out all the water.