Pump 1 can empty a pool in 9 hours while Pump 2 can empty the same pool in 12 hours. If the two pumps worked together, how long

Question

2 years ago

10

would it take them to empty the pool?
about 5 hours and 30 minutes
about 5 hours and 10 minutes
about 5 hours and 20 minutes
about 5 hours

1 answer:

ruslelena [56] · Answer 1 · 2023-05-05T00:58:07+03:00

8 0

Answer:

About 5 hr 10 min

Step-by-step explanation:

rate 1 = 1 pool / 9 hrs rate 2 = 1 pool / 12 hours

now find the time with both rates combined

1 pool / ( 1/9 + 1/12) = 1/ (7/36) = 36/7 hr = 5 1/7 hr = 5 hr 8.6 min