Question

One pump can fill a swimming pool in 8 hours and another pump can fill it in 10 hours. If both pumps are opened at the same time, how many hours will it take to fill the pool?

Answer 1

8 hours because the lesser one is 8 and it can fill a whole pool in 8 hours

Answer 2

one pump can fill 5/40 of the pool in an hour(8 hour pump), and the other can fill 4/40 of the pool in an hour(10 hour pump). if both pumps run at the same time, 9/40 of the pool is filled every hour. To fill the pool completely, it will take the pumps roughly 4 hours and 26 minutes.