wo pipes X and Y fill a tank in 15 hrs. and 20 hrs. respectively, while a third pipe ‘Z’ can empty the full tank in 25 hrs.  All the three pipes are opened in the beginning.  After 10 hrs. Z is closed.  In how much time, will the tank be full ?

Related Mcqs:

1. Two pipes can fill a tank in 10 hrs. and 12 hrs. respectively while a third pipe empties the full tank in 20 hrs.  If all the three pipes operate together , in how much time the tank will be filled ? 

   A. 7.5 hrs
   B. 5 hrs
   C. 7 hrs
   D. None of these

2. A leak in the bottom of a tank can empty the full tank in 6 hrs.  An inlet pipe fills water at the rate of 4 lit. a minute.  When the tank is full, the inlet is opened and due to the leak, the tank is empty in 8 hrs.  The capacity of the tank in liters is_________?

   A. 5,750 litres
   B. 5,760 litres
   C. 6,890 litres
   D. None of these

3. A leak in the lower portion of a tank can empty the full tank in 9 hrs.  An inlet pipe fills water at the rtae of 10 lit. a minute.  When the tank is full, the inlet is opened and due to leak, the tank is empty in 16 hrs.  How many litres does the cistern hold ?

   A. 12,342 litres.
   B. 12,444 litres
   C. 12,566 litres.
   D. None of thes

4. Two pipes can separately fill a tank in 20 and 30 hours respectively. Both the pipes are opened to fill the tank but when the tank is full, a leak develops in the tank through which one-third of water supplied by both the pipes goes out. What is the total time taken to fill the tank?

   A. 18 hrs
   B. 16 hrs
   C. 15 hrs
   D. 12 hrs

5. 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 solution R in the liquid in the tank after 3 minutes?

   A. 5/11
   B. 6/11
   C. 7/11
   D. 8/11

6. A tank is filled by three pipes with uniform flow. The first two pipes operating simultaneously fill the tank in the same 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?

   A. 6 hrs
   B. 10 hrs
   C. 15 hrs
   D. 30 hrs

7. Two pipes can fill a tank in 18 minutes and 15 minutes. An outlet pipe can empty the tank in 45 minutes. If all the pipes are opened when the tank is empty, then how many minutes will it take to fill the tank?

   A. 12
   B. 13
   C. 11
   D. 10

8. Two pipes A and B can separately fill a cistern in 60 min and 75 min respectively. There is a third pipe in the bottom of the cistern to empty it. If all the three pipes are simultaneously opened, then the cistern is full in 50 min. In how much time, the third pipe alone can empty the cistern?

   A. 90 min
   B. 100 min
   C. 110 min
   D. 120 min

9. A water tank is two-fifth full. Pipe A can fill a tank in 10 minutes and pipe B can empty it in 6 minutes. If both the pipes are open, how long will it take to empty or fill the tank completely?

   A. 6 min. to empty
   B. 6 min. to full
   C. 9 min. to empty
   D. 9 min. to full

10. Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 3 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank is?

    A. 60 gallons
    B. 100 gallons
    C. 120 gallons
    D. 180 gallons