Top 130 Pipe and cistern questions for Competitive Exams [ 100% FREE ]

Introducing an important aspect of the quantitative aptitude section: the Pipe and cistern questions. A common challenge candidates face in various competitive exams, be it banks, SSC, RRB, Insurance and more, is problems related to pipes and cisterns. In this comprehensive article, we delve deep into “Pipe and cistern questions“, ensuring you get the most effective preparation material.

For many, the term “Pipe and cistern questions” can seem daunting, but with the right approach and understanding of the “pipes and cisterns formula“, it becomes manageable. This is why we’re emphasizing on the crucial examples like “two pipes p and q together can fill a cistern” and “two pipes a and b can fill a cistern“. Both these examples will give you a clear perspective on how to approach these problems.

We also recognize the importance of language adaptability in preparation. Therefore, we have also incorporated “pipe and cistern questions in Hindi” and insights on “pipe and cistern in Hindi“. This ensures that you not only understand the crux of the “pipes and cisterns problems” but also can relate to them in a language you’re comfortable with.

Word problems, especially around the “pipes and cisterns formula“, have been a mainstay in competitive exams. While “two pipes p and q together can fill a cistern” or “two pipes a and b can fill a cistern” might seem similar, they can carry nuances that are essential for aspirants to grasp.

Pipes and Cisterns Formula :

Given below are aimportant formulas which shall help you solve the pipes and cistern based questions quicker and more efficiently:

  • If x hours are required to fill up a tank, then part filled in 1 hr =1/x
  • If y hours are required to empty the tank, then part emptied in 1 hour = 1/y
  • If a pipe can fill a tank in x hours and can empty the same tank in y hours. When both the pipes are opened at the same time, then the net part of the tank filled in 1 hr = {(xy) / (y-x)}, provided y>x
  • If a pipe can fill a tank in x hours and can empty the same tank in y hours. When both the pipes are opened at the same time, then the net part of the tank filled in 1 hr = {(xy) / (x-y)}, provided x>y
  • Net work done = (Sum of work done by Inlets) – (Sum of work done by Outlets)
  • One inlet can fill the tank in x hr and the other inlet can fill the same tank in y hrs, if both the inlets are opened at the same time, the time taken to fill the whole tank = {(xy) / (y+x)}
  • If two pipes take x and y hours respectively to fill a tank of water and a third pipe is opened which takes z hours to empty the tank, then the time taken to fill the tank = {1 / (1/x)+(1/y)+(1/z)} and the net part of the tank filled in 1 hr = (1/x)+(1/y)-(1/z)

The syllabus for competitive exams is vast, as we all know. But every topic, including “Pipe and cistern questions“, holds its weight. Therefore, giving due time to understand and practice these “pipes and cisterns problems” is paramount. Especially when considering the intense competition and the challenge to crack these exams.

In conclusion, this article offers an in-depth understanding of “Pipe and cistern questions“, covering essential examples like “two pipes p and q together can fill a cistern” and “two pipes a and b can fill a cistern“, not forgetting the importance of language with “pipe and cistern questions in Hindi” and “pipe and cistern in Hindi“.

Whether you’re just starting out or brushing up your skills, this article is your guide to excel. So, gear up and dive into the world of “Pipe and cistern questions” and ace your upcoming Government sector exams!

Top 130 Pipe and cistern questions for Competitive Exams :

91. Three pipes A, B and C can fill a tank in 12 hours. After working at it together for 3 hours, C is closed and A and B can fill the remaining part of the tank in 15 hours. How much time will the pipe C alone taken to fill the tank?

तीन पाइप A, B और C एक टैंक को 12 घंटे में भर सकते हैं। 3 घंटे तक एक साथ काम करने के बाद, C बंद है और A और B टैंक के शेष भाग को 15 घंटे में भर सकते हैं। टैंक को भरने के लिए अकेले पाइप C को कितना समय लगेगा?

A. 24 hours
B. 26 hours
C. 32 hours
D. 30 hours
E. None of these

Option “D” is correct.

A, B and C’s 1 hour work = 1/12

A, B and C’s 3 hour work = 3/12 = 1/4

Remaining work = 1 – (1/4) = 3/4

The remaining part will be filled by A and B in 15 hours. Then,

= > (3/4) *(A+B) = 15

= > (A+B)’s whole work = 15*(4/3) = 20 hr

(A+B)’s 1 hour work = 1/20

A, B and C’s 1 hour work = 1/12

C’s 1 hour work = (A + B + C) – (A+B)

= > (1/12) – (1/20)

= > 1/30

C can fill the tank in 30 hours

92. Three pipes A, B and C fill the tank in 12 hours, 16 hours and 30 hours respectively and they opened simultaneously. After 3 hours pipe A is closed and after 1 more hour pipe B is closed. How many hours required to pipe C to complete the remaining tank?

तीन पाइप A, B और C क्रमशः 12 घंटे, 16 घंटे और 30 घंटे में टैंक को भरते हैं और वे एक साथ खोले गए हैं। 3 घंटे बाद, पाइप A बंद किया गया है और 1 अधिक घंटे के बाद पाइप B बंद किया गया है। शेष टैंक को पूरा करने के लिए पाइप C को कितने घंटों की आवश्यकता है?

A. 12 hours
B. 10 hours
C. 11 hours
D. 9 hours
E. None of these

Option “C” is correct.

A=1/12

B=1/16

C=1/30

LCM of (12, 16, 30)=240

A complete one hour in 20 units

B complete one hour in 15 units

C complete one hour in 8 units

Work done by 3 hours (A + B+ C) = 60 + 45 + 24 =129 units

After one hour, (B + C) =15 + 8 = 23

Remaining work = 240 – 129 – 23 = 88

Remaining work done by C in = 88/8 = 11 hours

93. Pipe A and B can fill the tank in 15 minutes and 9 minutes respectively and pipe C empties the tank. If Pipes A, B and C opened together, after 5 minutes, pipes A and C closed and pipe B can fill the remaining tank in 2 minutes. Find the time taken by pipe C can empty the tank?

पाइप A और B टैंक को क्रमशः 15 मिनट और 9 मिनट में भर सकते हैं और पाइप C टैंक को खाली करता है। यदि पाइप A, B और C एक साथ खुलते हैं, तो 5 मिनट के बाद, पाइप A और C बंद हो जाते हैं और पाइप B शेष टैंक को 2 मिनट में भर सकता है। पाइप C द्वारा टैंक को खाली करने में लिया गया समय ज्ञात कीजिए?

A. 36 minutes
B. 60 minutes
C. 30 minutes
D. 45 minutes
E. None of these

Option “D” is correct.

The time taken by pipe C can empty the tank = x minutes

(1/15 + 1/9 – 1/x) * 5 + 2/9 = 1

(3/45 + 5/45 – 1/x) * 5 + 10/45 = 1

40/45 –5/x + 10/45 = 1

50/45 – 5/x = 1

50/45 = 1 + 5/x

50x/45 = x + 5

50x – 45x = 5 * 45

x = 5 * 45/5

x = 45 minutes

Pipe C can empty the tank in 45 minutes

94. Pipe A, B and C can fill the tank in 30 hours, 10 hours and 15 hours respectively. If Pipe A and C opened together. After y hours, pipe A closed and pipe B opened. If pipes B andC together fill the remaining tank in 3 hours, then find the value of y?

पाइप A, B और C टैंक को क्रमशः 30 घंटे, 10 घंटे और 15 घंटे में भर सकते हैं। यदि पाइप A और C एक साथ खुलते हैं। y घंटे के बाद, पाइप A बंद हो जाता है और पाइप B खुल जाता है। यदि एकसाथ पाइप B और C शेष टैंक को 3 घंटे में भरते हैं, तो y का मान ज्ञात कीजिए?

A. 6
B. 8
C. 5
D. 9
E. None of these

Option “C” is correct.

(1/30 + 1/15) * y + (1/15 + 1/10) * 3 = 1

(1/30 + 2/30) * y + (2/30 + 3/30) * 3 = 1

3y + 5 * 3 = 30

3y = 30 – 15

y = 15/3

y = 5

95. Time taken by Pipe B alone can fill a tank is 5/6th of the time taken by Pipe A alone to fill the tank and Pipe C alone can fill the tank in 30 minutes. If all the three pipes are opened together, they can fill the tank in 1/3rd of the time taken by Pipe A alone to fill the tank. Find the time taken by Pipe A alone to fill the tank.

अकेले पाइप B द्वारा टैंक को भरने में लिया गया समय केवल पाइप A द्वारा टैंक को भरने में लिए गए समय का 5/6 है और पाइप C अकेले टैंक को 30 मिनट में भर सकता है। यदि एक साथ तीनों पाइपों को खोल दिया जाता है, तो वे अकेले पाइप A द्वारा टैंक को भरने में लिए गए समय के 1/3 भाग में भर सकते हैं। अकेले पाइप A द्वारा टैंक को भरने में लिया गया समय ज्ञात कीजिए।

A. 24 minutes
B. 20 minutes
C. 25 minutes
D. 12 minutes
E. None of these

Option “A” is correct.

The ratio of the time taken by Pipe A to Pipe B to fill the tank = 6:5

Let the Time taken by Pipe A alone to fill the tank = 6x

Time taken by Pipe B alone to fill the tank = 5x

Time taken by all the three pipes together to fill the tank = 6x * 1/3 = 2x

1/6x + 1/5x + 1/30 = 1/2x

1/2x – (1/6x + 1/5x) = 1/30

1/2x – (5 + 6)/30x = 1/30

1/2x – 11/30x = 1/30

(15 – 11)/30x = 1/30

4/30x = 1/30

x = 4 minutes

Time taken by Pipe A alone to fill the tank = 6 * 4 = 24 minutes

96. Pipes P and Q together can fill the tank in 24 minutes and pipes Q and R can fill the tank in 60 minutes and 30 minutes respectively. If pipe P doubles its efficiency and pipe R reduced to half of its efficiency, then find the time taken by pipe P and R together to fill the tank?

एकसाथ पाइप P और Q टैंक को 24 मिनट में भर सकते हैं और पाइप Q और R टैंक को क्रमशः 60 मिनट और 30 मिनट में भर सकते हैं। यदि पाइप P अपनी दक्षता को दोगुना कर देता है और पाइप R अपनी दक्षता को आधी कर देता है, तो एक साथ पाइप P और R द्वारा टैंक को भरने में लिया गया समय ज्ञात कीजिये?

A. 27 minutes
B. 40 minutes
C. 15 minutes
D. 36 minutes
E. None of these

Option “C” is correct.

Pipe P alone fill the tank = 1/24 – 1/60 = 5/120 – 2/120 = 3/120 = 1/40 = 40 minuets

Pipe P double its efficiency:

The time taken by pipe P alone to fill the tank = 40 * 1/2 = 20 minutes

Pipe R reduced half of its efficiency:

The time taken by pipe R alone to fill the tank = 30 * 2 = 60 minutes

The time taken by pipes P and R together to fill the tank = 1/20 + 1/60 = (3 + 1)/60 = 4/60 = 1/15 = 15 minutes

97. Three pipes A, B and C can fill a tank in 12 hours. After working at it together for 3 hours, C is closed and A and B can fill the remaining part of the tank in 15 hours. How much time will the pipe C alone taken to fill the tank?

तीन पाइप A, B और C एक टंकी को 12 घंटे में भर सकते हैं। एक साथ 3 घंटे तक इस पर काम करने के बाद, C को बंद कर दिया जाता है और A और B टंकी के शेष भाग को 15 घंटे में भर सकते हैं। अकेले पाइप C को टंकी को भरने में कितना समय लगेगा?

A. 24 hours
B. 26 hours
C. 32 hours
D. 30 hours
E. None of these

Option “D” is correct.

A, B and C’s 1 hour work = 1/12

A, B and C’s 3 hour work = 3/12 = 1/4

Remaining work = 1 – (1/4) = 3/4

The remaining part will be filled by A and B in 15 hours. Then,

= > (3/4) *(A+B) = 15

= > (A+B)’s whole work = 15*(4/3) = 20 hr

(A+B)’s 1 hour work = 1/20

A, B and C’s 1 hour work = 1/12

C’s 1 hour work = (A + B + C) – (A+B)

= > (1/12) – (1/20)

= > 1/30

C can fill the tank in 30 hours

98. A, B and C can fill the tank in 10 min, 15 min and 20 min respectively. All the pipes began to fill the tank, but A and B closed 3 min and 5 min respectively before the tank filled. How much time taken to fill the tank?

A, B और C टंकी को क्रमशः 10 मिनट, 15 मिनट और 20 मिनट में भर सकते हैं। सभी पाइप टंकी को भरना शुरू करते हैं, लेकिन A और B को टंकी भरने से क्रमशः 3 मिनट और 5 मिनट पहले बंद कर देते हैं। टंकी को भरने में कितना समय लगा?

A. 8 6/17 min
B. 6 5/18 min
C. 7 7/13 min
D. 9 4/15 min
E. None of these

Option “C” is correct.

Given,

[(x – 3) / 10] + [(x – 5) / 15] + [x / 20] = 1

[6x – 18 + 4x – 20 + 3x] / 60 = 1

13x – 38 = 60

13x = 98

x = 98 / 13 = 7 7/13 min

99. Pipe A and B can fill a tank in 20 hours and 30 hours respectively while pipe C can empty the full tank in 40 hours. All are opened together, after 12 hours, pipe C closed. Find the time taken to fill the whole tank?

पाइप A और B एक टंकी को क्रमश: 20 घंटे और 30 घंटे में भर सकते हैं जबकि पाइप C पूरी टंकी को 40 घंटे में खाली कर सकता है। सभी को एक साथ खोला जाता है, 12 घंटे के बाद, पाइप C बंद हो जाता है। पूरे टंकी को भरने में लगने वाला समय ज्ञात कीजिये?

A. 16 hours 24 mins
B. 14 hours 48 mins
C. 15 hours 36 mins
D. 13 hours 40 mins
E. None of these

Option “C” is correct.

Total units = LCM (20, 30 and 40) = 120 units

Pipe A can fill = 6 units/hr

Pipe B can fill = 4 units/hr

Pipe C can empty = 3 units/hr

1 hour work = 6 + 4 – 3 = 7 units/hr

12 hour work = 7 * 12 = 84 units/hr

Remaining work = 120 – 84 = 36 units

Remaining tank can be filled by pipe A and B in,

= > 36 / (6 + 4) = 3 3/5 hour

Total time taken by fill the tank

= > 12 + 3 3/5 = 15 3/5 hour (or) = 15 hours 36 mins

100. Two inlet pipes can fill a tank in 10 and 12 minutes respectively and an outlet pipe can empty 2 gallons per minute. All the three pipes working together can fill the tank in 6 minutes. What is the capacity of the tank?

दो इनलेट पाइप(भरने वाले पाइप) एक टंकी को क्रमशः 10 और 12 मिनट में भर सकते हैं और एक आउटलेट पाइप(खाली करने का पाइप) 2 गैलन प्रति मिनट खाली कर सकता है। तीनों पाइप एक साथ कार्य करते हुए टंकी को 6 मिनट में भर सकते हैं। टंकी की क्षमता क्या है?

A. 60 gallons
B. 120 gallons
C. 180 gallons
D. 240 gallons
E. None of these

Option “B” is correct.

Work done by outlet pipe in 1 hour = 1/6 – (1/10 + 1/12) = -1/60 (negative represents Outlet)

Volume of 1/60 part = 2 gallons

Capacity of full tank = 2 * 60 = 120 gallons