Pipes and Cisterns - One Line Questions

1. A cistern can be filled by pipe A in 2 hours and by pipe B in 3 hours. Both pipes are opened. After some time, pipe B is closed. If the cistern is filled in 3 hours in total, after how much time was pipe B closed? — 2 hours
2. Tap P can fill a reservoir in 10 hours. Tap Q can fill it in 15 hours. If both taps are opened, after how much time should tap Q be closed so that the reservoir is filled in 7 hours? — 4 hours
3. Pipe X fills a tank in 8 hours. Pipe Y fills it in 6 hours. If they are opened together, after how much time should pipe Y be closed so that the tank is filled in 4 hours? — 2 hours
4. A cistern is filled by three pipes A, B, and C. Pipe A can fill it in 2 hours, Pipe B in 3 hours, and Pipe C in 4 hours. If they are opened together, what fraction of the cistern will be filled in 1 hour? — 11/12
5. Two pipes A and B can fill a cistern in 1 hour and 2 hours respectively. If they are opened together, what fraction of the cistern will be filled in 30 minutes? — 3/4
6. Two pipes A and B can fill a tank in 6 minutes and 8 minutes respectively. If they are opened together, what fraction of the tank will be filled in 3 minutes? — 5/8
7. A tap fills a cistern in 3 hours. It is opened for 1 hour. What fraction of the cistern is filled? — 1/3
8. A cistern can be filled by pipe A in 5 hours and by pipe B in 6 hours. If they are opened together, what fraction of the cistern will be filled in 2 hours? — 11/15
9. Two pipes A and B can fill a cistern in 20 minutes and 30 minutes respectively. If both pipes are opened together, what fraction of the cistern will be filled in 5 minutes? — 1/3
10. Pipe P can fill a cistern in 3 hours. Pipe Q can fill it in 4 hours. Pipe R can empty it in 2 hours. If all three pipes are opened together, how long will it take to fill the cistern? — 12 hours
11. Pipe 1 can fill a tank in 10 hours. Pipe 2 can fill it in 12 hours. Pipe 3 can empty it in 15 hours. If all three pipes are opened together, how long will it take to fill the tank? — 12 hours
12. Pipe A fills a tank in 20 minutes. Pipe B fills it in 30 minutes. Pipe C empties it in 60 minutes. If all three pipes are opened together, how long will it take to fill the tank? — 10 minutes
13. Pipe A can fill a tank in 15 minutes. Pipe B can fill it in 20 minutes. Pipe C can empty it in 30 minutes. If all three pipes are opened together, how long will it take to fill the tank? — 10 minutes
14. A pipe can fill a cistern in 4 hours. Due to a leakage, it takes 5 hours to fill the cistern. In how much time can the leakage empty the filled cistern? — 20 hours
15. Two pipes A and B can fill a cistern in 10 hours and 12 hours respectively. A third pipe C can empty it in 15 hours. If all three pipes are opened together, how long will it take to fill the cistern? — 20 hours
16. A cistern has two pipes. The first pipe can fill it in 30 minutes and the second pipe can fill it in 60 minutes. If both pipes are opened together, what is the time taken to fill the cistern? — 20 minutes
17. Pipe X fills a tank in 5 hours. Pipe Y empties it in 4 hours. If the tank is full, how long will it take to empty it if both pipes are opened? — 20 hours
18. A pipe can fill a tank in 6 hours. After 2 hours of working, half of the tank is filled. How much time will it take to fill the remaining half? — 4 hours
19. Tap A can fill a tank in 2 hours. Tap B can fill it in 3 hours. If they are opened on alternate hours, starting with Tap B, how long will it take to fill the tank? — 2.4 hours
20. A cistern is filled by pipe A in 2 hours and emptied by pipe B in 4 hours. If the cistern is 1/3 full and both pipes are opened, how long will it take to fill the remaining part? — 4 hours
21. Pipe X can fill a tank in 3 hours. Pipe Y can fill it in 4 hours. Pipe Z can empty it in 5 hours. If all three pipes are opened together, how long will it take to fill the tank? — 2 hours 40 minutes
22. A tap can fill a cistern in 5 hours. After 2 hours, it is closed. What fraction of the cistern is filled? — 2/5
23. A tap can fill a cistern in 8 hours. Due to leakage, it takes 10 hours to fill the cistern. In how much time can the leakage empty the filled cistern? — 40 hours
24. Pipe A can fill a tank in 12 hours. Pipe B can fill it in 15 hours. Pipe C can empty it in 10 hours. If all three pipes are opened together, how long will it take to fill the tank? — 20 hours
25. A cistern has two inlets, A and B, which can fill it in 10 minutes and 15 minutes respectively, and an outlet C which can empty it in 6 minutes. If all three pipes are opened, how long will it take to fill the cistern? — 30 minutes
26. Pipe X can fill a tank in 20 minutes. Pipe Y can fill it in 25 minutes. Pipe Z can empty it in 30 minutes. If all three pipes are opened together, how long will it take to fill the tank? — 25 minutes
27. Pipe P can fill a tank in 5 hours. Pipe Q can fill it in 10 hours. Pipe R can empty it in 15 hours. If all three pipes are opened together, how long will it take to fill the tank? — 3 hours
28. A tank is filled by pipe A in 2 hours and emptied by pipe B in 3 hours. If the tank is half-filled and both pipes are opened, how long will it take to fill the remaining half? — 3 hours
29. Pipe P fills a tank in 4 hours. Pipe Q fills it in 5 hours. Pipe R empties it in 10 hours. If all three pipes are opened together, how long will it take to fill the tank? — 4 hours
30. Two taps A and B can fill a tank in 12 minutes and 15 minutes respectively. There is also a third tap C which can empty the tank in 10 minutes. If all three taps are opened simultaneously, how long will it take to fill the tank? — 40 minutes
31. A cistern is filled by pipe A in 3 hours and by pipe B in 4 hours. If they are opened together, after how much time should pipe A be closed so that the cistern is filled in 2 hours? — 45 minutes
32. Two taps A and B can fill a tank in 30 minutes and 45 minutes respectively. There is a third tap C which can empty the tank in 60 minutes. If all three taps are opened simultaneously, how long will it take to fill the tank? — 36 minutes
33. Tap A can fill a tank in 4 hours. Tap B can fill it in 6 hours. If they are opened on alternate hours, starting with Tap A, how long will it take to fill the tank? — 4 hours 48 minutes
34. Two pipes A and B can fill a tank in 10 minutes and 15 minutes respectively. If they are opened together, how long will it take to fill 75% of the tank? — 5 minutes
35. A cistern can be filled by two pipes A and B in 12 minutes and 18 minutes respectively. If they are opened together, after how much time should pipe B be closed so that the cistern is filled in 10 minutes? — 6 minutes
36. Pipe P can fill a tank in 4 hours. Pipe Q can fill it in 6 hours. Pipe R can empty it in 8 hours. If all three pipes are opened together, how long will it take to fill the tank? — 4.8 hours
37. A tap can fill a cistern in 12 hours. Due to leakage, it takes 16 hours to fill the cistern. In how much time can the leakage empty the filled cistern? — 48 hours
38. A tap can fill a cistern in 7 hours. Due to leakage, it takes 8 hours to fill the cistern. In how much time can the leakage empty the filled cistern? — 56 hours
39. If two pipes A and B can fill a cistern in 10 hours and 15 hours respectively, how long will it take for both pipes to fill the cistern together? — 6 hours
40. A cistern is filled by pipe A in 3 hours and emptied by pipe B in 6 hours. If both pipes are opened, how long will it take to fill the cistern? — 6 hours
41. A cistern can be filled by two pipes A and B in 20 minutes and 30 minutes respectively. If they are opened together, after how much time should pipe A be closed so that the cistern is filled in 15 minutes? — 6 minutes
42. Pipe X can fill a tank in 20 minutes. Pipe Y can fill it in 30 minutes. Pipe Z can empty it in 15 minutes. If all three pipes are opened, how long will it take to fill the tank? — 60 minutes
43. Pipe A can fill a tank in 12 hours and Pipe B can fill it in 18 hours. Both pipes are opened, but Pipe A is closed after 3 hours. How much longer will Pipe B take to fill the remaining part of the tank? — 12 hours
44. Two pipes A and B can fill a cistern in 3 hours and 5 hours respectively. A third pipe C can empty it in 2 hours. If all three pipes are opened, in how much time will the cistern be filled? — 7.5 hours
45. A cistern is filled by pipes A and B in 15 minutes and 20 minutes respectively. Both pipes are opened. After 6 minutes, pipe B is closed. How much time will pipe A take to fill the remaining part of the cistern? — 10 minutes
46. Pipe A can fill a tank in 4 hours, and Pipe B can empty it in 6 hours. If both pipes are opened simultaneously, in how much time will the tank be filled? — 8 hours
47. A cistern is filled by pipe A in 4 hours and emptied by pipe B in 6 hours. If both pipes are opened, how long will it take to fill the cistern? — 12 hours
48. Two pipes A and B can fill a cistern in 45 minutes and 60 minutes respectively. A third pipe C can empty it in 30 minutes. If all three pipes are opened together, how long will it take to fill the cistern? — 90 minutes
49. A cistern is filled by pipe A in 6 hours and emptied by pipe B in 4 hours. If both pipes are opened, will the cistern be filled or emptied, and in how much time? — Emptied in 12 hours
50. A cistern can be filled by pipe A in 3 hours and emptied by pipe B in 5 hours. If both pipes are opened, will the cistern be filled or emptied, and in how much time? — Filled in 7.5 hours
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