Quiz Discussion

A cistern has two taps which fill it in 12 minutes and 15 minutes respectively. There is also a waste pipe in the cistern. When all the pipes are opened, the empty cistern is full in 20 minutes. How long will the waste pipe take to empty the full cistern?

• 1]

  12 min

• 2]

  10 min

• 3]

  8 min

• 4]

  16 min

Two pipes A and B can fill a cistern in 37.5 minutes and 45 minutes respectively. Both pipes are opened. The cistern will be filled in just half an hour, if the B is turned off after:

• 1] 5 min.
• 2] 9 min.
• 3] 10 min.
• 4] 15 min.

A vessel has three pipes connected to it , two to supply liquid and one to draw liquid. The first alone can fill the vessel in hours, the second in 3 hours and the third can empty it in hours. If all the pipes are opened simultaneously when the vessel is half full, how soon will it be emptied?

• 1]

  hours

• 2]

   hours

• 3]

  hours

• 4]

  None of these

An electric pump can fill a tank in 3 hours. Because of a leak in the tank, it  took 321​ hours to fill the tank. The leak can drain all the water off the tank in

• 1]

  12 hours

• 2]

  10 1/2 hours

• 3]

  6 1/2 hours

• 4]

  21 hours

Pipe A can fill a tank in 4 hours and pipe B can fill it 6 hours. If they are opened on alternate hours and if pipe A is opened first then in how many hours, the tank shall be full ?

• 1]

  hours

• 2]

  hours

• 3]

  hours

• 4]

  hours

A tap can fill a tank in 6 hours. After half the tank is filled, three more similar taps are opened. What is the total time taken to fill the tank completely?

• 1] 3 hrs 15 min
• 2] 3 hrs 45 min
• 3] 4 hrs
• 4] 4 hrs 15 min

A tank with capacity T liters is empty. If water flows into the tank from pipe X at the rate of x liters per minute and water is pumped out by Y at the rate of y liters per minute and x > y, then how many minutes will the tank be filled?

• 1]

  (x - y) 60 T minutes

• 2]

  (T - x) minutes

• 3]

    minutes

• 4]

   minutes

Three taps A, B and C can fill a tank in 12, 15 and 20 hours respectively. If A is open all the time and B and C are open for one hour each alternately, the tank will be full in:

• 1]

  6 hours

• 2]

  hours

• 3]

  7 hours

• 4]

  hours

A pump can fill a tank with water in 2 hours. Because of a leak, it took hours to fill the tank. The leak can drain all the water of the tank in:

• 1]

  hours

• 2]

  7 hours

• 3]

  8 hours

• 4]

  14 hours

Two pipes A and B can fill a tank with water in 30 minutes and 45 minutes respectively. The third pipe C can empty the tank in 36 minutes. First A and B are opened. After 12 minutes C is opened. Total time ( in minutes ) in which the tank will be filled up is -

• 1] 12 minutes
• 2] 24 minutes
• 3] 30 minutes
• 4] 36 minutes