Question 900179
the first pump obviously pumps faster and pumps in 10hr. with the 2nd pump, it pumps in 6hr. You would do 10-6 because you know how long the first one pumps and you subtract it to find how much faster does the 2nd one pump. then you add 4 to the 10 which is 14hr. 


 Answer: 14hr for the 2nd pump to fill the pool