Pipe A can fill a tank in 15 hours, pipe B in 10 hours and pipe C in 3 hours. If all the pipes are open, in how many hours will the tank be filled? Choose the correct choice from the following choices.
A) 2  B) 2.5  C) 3  D) 5  E) None
Sol.   Part filled by (A + B + C) in 1 hour = (1/15 + 1/10 + 1/3) = 1/2.   âˆ´ All the three pipes together will fill the tank in 2 hours.   2nswer 2
<result>A</result>
Pipe A can fill a tank in 15 hours, pipe B in 10 hours and pipe C in 3 hours. If all the pipes are open, in how many hours will the tank be filled?