Pipes A and B together can fill a tank in 16 hours, whereas pipe C alone can empty the full tank in 24 hours. A and B were opened together for 10 hours and then closed. Pipe C was then opened. The tank will now be emptied by C in:
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. 15 hours
Efficiency of pipe A and pipe B = 1/16 th part/hr
Part of the tank filled in 10 hrs = 10/16
Efficiency of pipe C = 1/24 th part/hr
Time taken to empty 10/16 th part =10/16 × 24 = 15 hrs
Pipe C will empty the tank in 15 hrs