WBCS.LIVE practice question

Two pipes can fill a tank in 20 hours and 60 hours respectively. A third pipe is a drainage pipe. If all three pipes are opened together, the tank is filled in 40 hours. How much time will it take for the drainage pipe to empty the filled tank?

Solve this multiple-choice question and check the correct answer with its explanation below.

Answer options

  1. 24 hrs
  2. 28 hrs
  3. 20 hrs
  4. 30 hrs

Correct answer and explanation

Correct answer: 24 hrs