Question

ary Egan needs to drain his 21 comma 000​-gallon inground swimming pool to have it resurfaced. He uses two pumps to drain the pool. One drains 15 gallons of water a minute while the other drains 20 gallons of water a minute. If the pumps are turned on at the same time and remain on until the pool is​ drained, how long will it take for the pool to be​ drained?

Answer 1

600 minutes = 10 hours

Explanation:

Egan has to drain 21 000 ga of water out of the pool. Let the number of minutes it takes him to drain the pool be x minutes. The equation for determining x can be set up and solved as follows:

`(15 ga)/(min)*xmin+(20ga)/(min)*xmin = 21000ga\\\\15x+20x=21000\\\\35x= 21000\\\\x = 600`

600 minutes = 10 hours