Ryan moved into a new house with a 1750 gallon pool and needs to fill it. He can't figure out how to close his pool drain. It fills up in 1458 minutes,but it drains in 2187 1/2 minutes. When will it be full?

Question

Ryan moved into a new house with a 1750 gallon pool and needs to fill it.  He can't figure out how to close his pool drain.  It fills up in 1458 minutes,but it drains in 2187 1/2 minutes.  When will it be full?

Damon · Answer

filling rate = 1750/1458 = 1.20 gal/min drain rate = 1750/2187.5 = .80 gal/min fill rate with drain open = 1.2-.8 = .4 gal/min 1750 gal/ .4 gal/min = 4375 minutes or about 73 hours