Egan needs to drain his 21,000 -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?

Question

Journey Soto

Mathematics

9 March, 11:48

Egan needs to drain his 21,000 -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?

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Answers (1)

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Immanuel Cannon · Answer 1

600 minutes

Step-by-step explanation:

The total rate of the Pump is gotten first

15 + 20 = total rates of 35 gallon per hour.

rate = volume / time.

Volume = rate * time

21,000 = 35 * t

t = 21,000/35

t = 600 minutes.

To check the volume each pump will pump out.

pump A 15 * 100 = 9000 gallons

Pump B 20 * 600 = 12000 gallons.

12,000+9,000 = 21,000 which gives the total gallons of the swimming pool back