Pipe A can fill a tank in 8 hours, pipe B in 16 hours and pipe C in 16 hours. If all the pipes are open, in how many hours will the tank be filled? Choose the correct choice from the following answers:
A) 2
B) 3
C) 4
D) 5
E) 6
Part filled by A + B + C in 1 hour = 1/8 + 1/16+ 1/16= 1/4   All the three pipes together will fill the tank in 4 hours.   Answer: 4
<result>C</result>
Pipe A can fill a tank in 8 hours, pipe B in 16 hours and pipe C in 16 hours. If all the pipes are open, in how many hours will the tank be filled?