Problema Solution
A swimming pool can be filled in 12 hours and drained in 20 hours. If the pool is empty and the drain is open, how long will it take to fill the pool?
Answer provided by our tutors
the rate of the filling is 1/12 pools per hour
the rate of the draining is 1/20 pools per hour
let x = the hours needed for the poll to fill if the drain is open
1/12 - 1/20 = 1/x
by solving we find
x = 30 hr
click here to see the step by step solution of the system of equations
it will take 30 hours to fill the pool.