A drain can empty the swimming pool in 3 days. A second drain can empty the pool in 2 days. How long will it take to empty the pool if both drains are used?

Question

How long will it take to empty the pool f both drains are used?

Answer 1

This is a unit rate question. How much of the pool gets drained in ONE day. Drain A can do 1/3 in a day, drain B can do 1/2 in a day. Using a common denominator, we see that together they can drain 5/6 of the pool in a day. The remaining portion of the pool is 1/5 of the amount they drained in a full day yesterday, so they will need another 1/5 of a day.

 

So, the total time draining together should be 1 1/5 days.

 

I think. :-)