Problema Solution
Pipe A can fill a tank in 10 hours and pipe B can fill the same tank in 8 hours.It takes 20 hours for the tank to drain. Using both pipes, how long will it take to fill the tank with the drain open?
Answer provided by our tutors
1 hour work of Pipe A = 1/10
1 hour work of Pipe B = 1/8
1 hour it get emptied = 1/20
so to fill the tank ---
1/10 + 1/8 - 1/20
solving we get
7/40
the tank will be filled in 40/7 hours = 5 5/7 hours