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

Total Questions: 39

1. 6 pipes, all of the same type, are required to fill a tank in 1 h 20 min. How long will it take if only 5 pipes of the same type are used? [RRB NTPC 10/02/2021 (Morning)]

Correct Answer: (c) 1 h 36 min
Solution:

6 pipe × 80 min = 5 pipe × T
T = 96 mins ⇒ 1 hr 36 min

2. Pipes A and B are fitted to a tank. A is the filling pipe and B can be used for filling or emptying at the same rate. When B is used for filling, it takes time ‘t’ along with A to fill the tank. If it is used for emptying when A is filling the tank, the time taken for the tank to fill up would be ‘5t’. Find the ratio of the rates of A and B. [RRB NTPC 03/04/2021 (Morning)]

Correct Answer: (c) 3 : 2
Solution:

3. A tap can fill a tank in 6 hours. After half the tank is filled, three more similar taps are opened. What is the total time taken for the tank to get filled? [RRB JE 31/05/2019 (Evening) ]

Correct Answer: (d) 3 hours 45 minutes
Solution:

According to the question Let total work is 6 unit and A tap can fill a tank in 6 hours then 1 hours = 6/6
1 unit Given that half of the tank is full then remaining is 3 unit according to question = 3/4 × 60 ⇒ 45 minutes
Total time taken to get filled Tank = 3 hours 45 minutes

4. An inlet pipe will fill a tank in 10 minutes. There are two outlets that can empty the tank separately in 12 and 15 minutes respectively. If all the pipes are opened and water starts filling up the tank, in what time will the tank get filled or emptied? [RRB JE 01/06/2019 (Morning)]

Correct Answer: (a) Emptied in 20 minutes
Solution:

5. Tank ‘A’ is two-fifths full. Pipe P can fill it in 10 minutes while pipe Q can empty it in 6 minutes. In what time will the tank get empty, if both P and Q are opened? [RRB JE 01/06/2019 (Morning)]

Correct Answer: (b) 6 minutes
Solution:

6. Two taps can separately fill a cistern in 20 minutes and 25 minutes. Both taps are open for 10 minutes after which the slower one is closed. How long will it take to fill the remaining portion by the other tap alone ? [RRB JE 01/06/2019 (Afternoon) ]

Correct Answer: (d) 2 minutes
Solution:

7. A cistern can be filled in 9 hours. But due to a leak, it takes one hour more. If the cistern is full, in what time will it become empty due to the leak ? [RRB JE 01/06/2019 (Evening) ]

Correct Answer: (c) 90 hours
Solution:

8. Two pipes P and Q together can fill a cistern in 4 hours. When opened separately, Q will take 6 hours more than P to fill the cistern. In how much time can P alone fill the cistern? [RRB JE 02/06/2019 (Morning)]

Correct Answer: (b) 6 hours
Solution:

9. Two pipes can fill a tank in 20 and 24 minutes respectively. There is an outlet in the tank that can empty it at 3 gallons per minute. If all the pipes are opened, the tank gets filled in 15 minutes. Find the capacity of the tank. [RRB JE 02/06/2019 (Morning)]

Correct Answer: (d) 120 gallons
Solution:

10. Pipe P works twice as fast as pipe Q and Q is twice as fast as pipe R. A tank is filled by all the three pipes together in 8 hours. How much time will Q alone take to fill the tank ? [RRB JE 26/06/2019 (Morning) ]

Correct Answer: (d) 28 hours
Solution: