A pipe can fill a tank completely in 10 hrs. However at half the height of the tank there is a leakage that can empty half of the tank in 10 hrs. In how much time will the tank be filled?

1) 9 hrs
2) 10 hrs
3) 20 hrs
4) 15 hrs
5) 25 hrs

• Ans - (c)
  
  A pipe takes 5 hour to do (1/2) unit of work.
  Remaining half unit of work = (1/2)
  Now, pipe will take 5 hour to fill a tank and 10 hour to empty half of the tank to accomplish 1 unit of work.
  Therefore, for remaining (1/2) unit it takes ----> (1/2)[1/5 - 1/10] = 1/20 => 20 hour.
• 11 years agoHelpfull: Yes(0) No(0)