Quiz Discussion

A water tap fills a tub in 'p' hours and a sink at the bottom empties it in 'q' hours. If p < q and both tap and sink are opened the tank is filled in 'r' hours, then the relation between p, q, r :

• 1]

  1/r = 1/p +1/q

• 2]

  1/r = 1/p -1/q

• 3]

  r = p + q

• 4]

  r = p - q

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 can be filled by pipe A in 2 hours and pipe B in 6 hours. At 10 A.M. pipe A was opened. At what time will the tank be filled if pipe B is opened at 11 A.M. ?

• 1] 12.45 A.M.
• 2] 5 P.M.
• 3] 11.45 A.M.
• 4] 12 P.M.

Pipes A and B can fill a tank in 5 and 6 hours respectively. Pipe C can empty it in 12 hours. If all the three pipes are opened together, then the tank will be filled in:

• 1]

  hours

• 2]

  hours

• 3]

  hours

• 4]

  hours

12 buckets of water fill a tank when the capacity of each bucket is 13.5 litres. How many buckets will be needed to fill the same tank, if the capacity of each bucket is 9 litres?

• 1] 8
• 2] 15
• 3] 16
• 4] 18

Three pipes A, B and C can fill a tank from empty to full in 30 minutes, 20 minutes, and 10 minutes respectively. When the tank is empty, all the three pipes are opened. A, B and C discharge chemical solutions P, Q and R respectively. What is the proportion of the solution R in the liquid in the tank after 3 minutes?

• 1]

  

• 2]

  

• 3]

  

• 4]

  

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

Three pipes A, B and C can fill a tank in 6 hours. After working at it together for 2 hours, C is closed and A and B can fill the remaining part in 7 hours. The number of hours taken by C alone to fill the tank is:

• 1] 10
• 2] 12
• 3] 14
• 4] 16

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

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