Pipe and Cistern (Railway Maths) (Part – I)

Total Questions: 50

41. Pipe A can fill 50% of a tank in 4 hours and pipe B can completely fill the same tank in 12 hours. If both the pipes are opened at the same time, then in how much time will the empty tank be completely filled ? [Level 6 (09/05/2022) Shift 2 ]

Correct Answer: (b) 4 hours 48 minutes
Solution:

42. A pipe can fill an empty tank in 12.5 hours. At the bottom of the tank there was a leakage point which can drain the completely filled tank in 17.5 hours. The leakage point could be closed after 14 hours of opening the pipe to fill the tank. What was the total time taken (in hours) to fill the tank ? [Level 5 (15/06/2022) Shift 2 ]

Correct Answer: (a) 22.5
Solution:

43. Pipes A and B can fill an empty tank completely in 42 minutes and 56 minutes respectively. Pipe C alone can empty the full tank in 84 minutes. All the three pipes are opened together for 8 minutes and then C is closed. In how much time (In minutes) will A and B together fill the remaining part of the tank? [Level 2 (16/06/2022) Shift 3 ]

Correct Answer: (a)
Solution:

44. Pipes A and B can fill a tank in 30 hours and 45 hours, respectively while pipe C alone can empty the full tank in 20 hours. When the tank is full, C alone is opened for 8 hours and then closed and pipes A and B are opened together at the same time. Now, how much time will pipe A and B together take to fill the tank completely ? [Level 3 (17/06/2022) Shift 2 ]

Correct Answer: (d) 7.2 hours
Solution:

45. A tank has 3 taps to fill water. The first tap takes 6 h, the second tap takes 1 day and the third tap takes 18 h to fill the tank. But there was a hole at the bottom, capable of emptying the completely filled tank in 18 h. The hole was detected after 1 h and was immediately fixed. How long will it take to fill the tank using all the three taps ? [RRB NTPC 10/01/2021 (Morning) ]

Correct Answer: (a)
Solution:

46. A water tank is made up of an aluminium sheet 3 cm thick. The tank is open at the top. It’s external dimensions are 1.30m, 1.06m and height 8.3 m. What is the cost of painting the inner surface of the tank at 50 paise per 100 sq m. [RRB NTPC 10/01/2021 (Evening) ]

Correct Answer: (e) *
Solution:

47. A tank has two inlets, A and B, which can fill it in 15 hours and 20 hours, respectively. An outlet C can empty the full tank in 12 hours. If A, B, and C are opened together when the tank is empty, then in how many hours will the tank be filled ? [RRB NTPC 20/01/2021 (Morning) ]

Correct Answer: (b) 30 hours
Solution:

48. Tap A can fill a tank in 6 h, whereas Tap B can fill it in 8 h. Tap C can empty the same tank in 4 h. If all the taps are opened together, how long will it take to fill the tank? [RRB NTPC 28/01/2021 (Morning)]

Correct Answer: (d) 24 h
Solution:

49. An inlet pipe can fill the tank in 4 h and an outlet pipe can empty the tank in 6 h. By mistake, both the pipes are kept open. Find the number of hours in which the tank will be half-full. [RRB NTPC 30/01/2021 (Morning)]

Correct Answer: (b) 6 h
Solution:

50. A tank can be filled by 5 pipes in 80 minutes. How long will it take to fill the tank by 8 pipes of same dimensions? [RRB NTPC 05/02/2021 (Morning)]

Correct Answer: (a) 50 minutes
Solution: