Quiz Discussion

Three pipes P, Q and R can separately fill a cistern in 4, 8 and 12 hours respectively. Another pipe S can empty the completely filled cistern in 10 hours. Which of the following arrangements will fill the empty cistern in less time than others?

• 1] Q alone is open
• 2] P, R and S are open
• 3] P and S are open
• 4] P, Q and S are open

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

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

Two pipes A and B can fill a tank in 20 and 30 minutes respectively. If both the pipes are used together, then how long will it take to fill the tank?

• 1] 12 minutes
• 2] 15 minutes
• 3] 25 minutes
• 4] 50 minutes

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 tank is filled by three pipes with uniform flow. The first two pipes operating simultaneously fill the tank in the same time during which the tank is filled by the third pipe alone. The second pipe fills the tank 5 hours faster than the first pipe and 4 hours slower than the third pipe. The time required by the first pipe is:

• 1] 6 hours
• 2] 10 hours
• 3] 15 hours
• 4] 30 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

A tank is 7 metre long and 4 meter wide wide. At what speed should water run through a pipe 5 cm broad and 4 cm deep so that in 6 hours and 18 minutes water level in the tank rises by 4.5 meter?

• 1] 10 km/hours
• 2] 12 km/hours
• 3] 8 km/hours
• 4] None of these

Two pipes A and B can fill a tank in 15 minutes and 20 minutes respectively. Both the pipes are opened together but after 4 minutes, pipe A is turned off. What is the total time required to fill the tank?

• 1] 10 min. 20 sec.
• 2] 11 min. 45 sec.
• 3] 12 min. 30 sec.
• 4] 14 min. 40 sec.

A water tank can be filled by a tap in 30 minutes and another tap can fill it in 60 minutes. If both taps are kept open for 5 minutes and then the first tap is closed, how long will it take foe the tank to be filled ?

• 1] 20 minutes
• 2] 25 minutes
• 3] 30 minutes
• 4] 45 minutes