Pipe and Cistern MCQ Quiz - Objective Question with Answer for Pipe and Cistern - Download Free PDF

Last updated on Jun 12, 2025

Quantitative Aptitude is a vast and vital section for many recruitment exams or placements such as IBPS, RRB, SBI, IPPB, LIC AAO, GIC AO, UIIC AO, NICL AO, etc. This section comprises Pipe and Cistern Questions, which play an important role in testing the candidates’ critical thinking abilities. In this article, you will find numerous Pipe and Cistern MCQ Quiz questions along with their solutions and explanations. Begin solving Pipe and Cistern Objective Questions now and start with your preparation.

Latest Pipe and Cistern MCQ Objective Questions

Pipe and Cistern Question 1:

Two inlet pipes A and B working together for 4 hours fill 72 units of water in a tank having capacity 160 units. If A alone can fill the tank in 20 hours, the time taken by B alone to fill the tank is 

  1. 25 hours
  2. 15hours
  3. 21 hours
  4. 16 hours

Answer (Detailed Solution Below)

Option 4 : 16 hours

Pipe and Cistern Question 1 Detailed Solution

Given:

Tank capacity = 160 units

Pipes A and B together fill 72 units in 4 hours

Pipe A alone fills the tank in 20 hours

Formula used:

Rate of filling = Work done / Time

Rate of A + Rate of B = Combined rate

Time taken = Tank capacity / Rate

Calculation:

Rate of A = Tank capacity / Time taken by A

⇒ Rate of A = 160 / 20 = 8 units/hour

Rate of A + Rate of B = Combined rate

Combined rate = Total water filled / Time

⇒ Combined rate = 72 / 4 = 18 units/hour

⇒ Rate of B = Combined rate - Rate of A

⇒ Rate of B = 18 - 8 = 10 units/hour

Time taken by B = Tank capacity / Rate of B

⇒ Time taken by B = 160 / 10 = 16 hours

∴ The correct answer is option (4).

Pipe and Cistern Question 2:

Pipe A can fill a tank in 30 minutes and Pipe B can fill it in 45 minutes. But third Pipe C can empty a full tank in 15 minutes. A and B are kept open for 15 minutes in the beginning and then C is also opened. Since then the time required (in minutes) to empty the tank is   

  1. 15
  2. 45
  3. 75
  4. 90

Answer (Detailed Solution Below)

Option 3 : 75

Pipe and Cistern Question 2 Detailed Solution

Given:

Pipe A fills tank in 30 min → Rate = 1/30

Pipe B fills tank in 45 min → Rate = 1/45

Pipe C empties tank in 15 min → Rate = -1/15

A and B opened for 15 minutes, then C is also opened

Formula used:

Work = Rate × Time

Calculation:

Work done by A and B in 15 min:

= 15 × (1/30 + 1/45) = 15 × 5/90 = 5/6 of tank is filled

Now, A + B + C rate = 1/30 + 1/45 - 1/15

LCM = 90 → (3 + 2 - 6)/90 = -1/90 (i.e. tank is emptying)

Remaining tank = 5/6

Time to empty 5/6 at rate of 1/90:

= (5/6) ÷ (1/90) = (5/6) × 90 = 75 minutes

∴ Time required to empty the tank = 75 minutes

Pipe and Cistern Question 3:

A cistern has an inlet pipe and an outlet pipe. Inlet pipe can fill three-fourth of the cistern in 24 minutes while outlet pipe can empty the one-third filled cistern in 16 minutes. If both the pipes are opened together, then the cistern will be completely filled in-

  1. 96
  2. 92
  3. 84
  4. 75
  5. 102

Answer (Detailed Solution Below)

Option 1 : 96

Pipe and Cistern Question 3 Detailed Solution

Given:

Inlet pipe can fill three-fourths of the cistern in 24 minutes.

Outlet pipe can empty one-third of the cistern in 16 minutes.

Calculations:

Rate of the inlet pipe = (3/4) cistern / 24 minutes = 3 / (4 × 24) = 1 / 32 cistern per minute.

Rate of the outlet pipe = (1/3) cistern / 16 minutes = 1 / (3 × 16) = 1 / 48 cistern per minute.

When both pipes are opened together, the combined rate is:

Combined rate = Rate of inlet pipe - Rate of outlet pipe = 1/32 - 1/48

To subtract, find the LCM of 32 and 48, which is 96:

1/32 = 3/96, and 1/48 = 2/96, so combined rate = (3/96) - (2/96) = 1/96 cistern per minute.

Thus, the cistern will be filled in 96 minutes.

∴ The cistern will be completely filled in 96 minutes.

Pipe and Cistern Question 4:

Pipe A can fill a tank in 816 minutes and Pipe B can empty the same tank in 1020 minutes. If both pipes are opened together, how many hours will it take to fill the empty tank?

  1. 70
  2. 66
  3. 72
  4. 68

Answer (Detailed Solution Below)

Option 4 : 68

Pipe and Cistern Question 4 Detailed Solution

Given:

Pipe A can fill the tank in 816 minutes.

Pipe B can empty the tank in 1020 minutes.

Formula used:

Efficiency of Pipe A = 1 / 816 (since it fills the tank in 816 minutes)

Efficiency of Pipe B = -1 / 1020 (since it empties the tank in 1020 minutes)

Calculations:

When both pipes are opened together, the net efficiency is the sum of their efficiencies:

Net efficiency = (1 / 816) - (1 / 1020)

To calculate this, we first find the LCM of 816 and 1020, which is 8160:

Net efficiency = (10 / 8160) - (8 / 8160) = 2 / 8160

The time taken to fill the tank is the inverse of the net efficiency:

Time = 8160 / 2 = 4080 minutes

Convert this time into hours:

Time in hours = 4080 / 60 = 68 hours

∴ It will take 68 hours to fill the empty tank when both pipes are opened together.

Pipe and Cistern Question 5:

Pipe A can fill a tank in 780 minutes and Pipe B can empty the same tank in 975 minutes. If both pipes are opened together, how many hours will it take to fill the tank?

  1. 67
  2. 65
  3. 69
  4. 63

Answer (Detailed Solution Below)

Option 2 : 65

Pipe and Cistern Question 5 Detailed Solution

Given:

Pipe A can fill the tank in 780 minutes

Pipe B can empty the tank in 975 minutes

Formula used:

Work = LCM of times taken

Efficiency = Work ÷ Time

Net work = Filling efficiency - Emptying efficiency

Time = Total work ÷ Net efficiency

Calculations:

LCM of 780 and 975 = 50700 units (Total work)

⇒ A’s 1 min work = 50700 ÷ 780 = 65 units

⇒ B’s 1 min work = 50700 ÷ 975 = 52 units

⇒ Net 1 min work = 65 - 52 = 13 units

⇒ Time = 50700 ÷ 13 = 3900 minutes

⇒ Convert to hours: 3900 ÷ 60 = 65 hours

∴ The tank will be filled in 65 hours.

Top Pipe and Cistern MCQ Objective Questions

A cistern has two pipes one can fill it with water in 16 hours and other can empty it in 10 hours. In how many hours will the cistern be emptied if both the pipes are opened together when 1/5th of the cistern is already filled with water?

  1. 11.4 hours
  2. 3.66 hours
  3. 5.33 hours
  4. 8.33 hours
  5. None of these

Answer (Detailed Solution Below)

Option 3 : 5.33 hours

Pipe and Cistern Question 6 Detailed Solution

Download Solution PDF

Shortcut Trick

F2 Shraddha Vaibhav (Black Diag) 06.04.2021 D9

If both pipes are open, total efficiency = (A + B) = 5 + (-8) = -3 units

According to question,

Amount of water in the tank = (1/5) × 80 = 16 units

Time taken to empty the tank = work/efficiency = 16/((-3)) = 5.33 hours

Alternate Method

GIVEN :

Time by which pipe A can fill the tank = 16 hours

Time by which pipe B can empty the tank = 10 hours 

The cistern is (1/5)th full.

CONCEPT :

Total work = time × efficiency

CALCULATION :

Work Time Efficiency
A 16 80/16 =  5
B 10 80/10 = (-8)

total work (LCM)

80  


Negative efficiency indicates pipe B is emptying the tank.

If both pipes are open, total efficiency = (A + B) = 5 + (-8) = -3 units

From the total efficiency it is clear that when both are opened, the tank is being emptied. 

Amount of water in the tank = (1/5) × 80 = 16 units

The water level will not rise as the total action is emptying when both are opened together.

Time taken to empty the tank = work/efficiency = 16/((-3)) = 5.33 hours

∴ Time taken to empty the tank is 5.33 hours.

Two pipes, when working one at a time, can fill a cistern in 3 hours and 4 hours, respectively while a third pipe can drain the cistern empty in 8 hours. All the three pipes were opened together when the cistern was 1/12 full. How long did it take for the cistern to be completely full?

  1. 2 hours
  2. 1 hour 45 minutes
  3. 2 hour 11 minutes
  4. 2 hour 10 minutes

Answer (Detailed Solution Below)

Option 1 : 2 hours

Pipe and Cistern Question 7 Detailed Solution

Download Solution PDF

Given:

First pipe can fill the cistern = 3 hours

Second pipe can fill the cistern = 4 hours

Third pipe can drain the cistern = 8 hours

Calculation:

Let the total amount of work in filling a cistern be 24 units. (LCM of 3, 4 and 8)

Work done by pipe 1 in 1 hour = 24/3 = 8 units.

Work done by pipe 2 in 1 hour = 24/4 = 6 units.

Work done by pipe 3 in 1 hour = 24/ (-8) = -3 units

Total work done in 1 hour = 8 + 6 – 3 = 11 units

The time required to complete 11/12th of the work = 11/12 × 24/ 11 = 2 hours

∴ The correct answer is 2 hours.

An inlet pipe can fill an empty tank in \(4\frac{1}{2}\) hours while an outlet pipe drains a completely filled tank in \(7\frac{1}{5}\) hours. The tank is initially empty. and the two pipes are alternately opened for an hour each, till the tank is completely filled, starting with the inlet pipe. In how many hours will the tank be completely filled? 

  1. 24
  2. \(20\frac{1}{4}\)
  3. \(20\frac{3}{4}\)
  4. \(22\frac{3}{8}\)

Answer (Detailed Solution Below)

Option 3 : \(20\frac{3}{4}\)

Pipe and Cistern Question 8 Detailed Solution

Download Solution PDF

Given: 

An inlet pipe can fill an empty tank in \(4\frac{1}{2}\) hours while an outlet pipe drains a completely filled tank in \(7\frac{1}{5}\) hours.

Concept used:

Efficiency = (Total work / Total time taken)

Efficiency = work done in a single day 

Calculation:Time taken by A = 9/2 hours

Time taken by B = 36/5
 
Capacity of tank = LCM(9/2, 36/5) = 36 units
 
Efficiency of A = 36/(9/2) = 8 units
 
Efficiency of B = 36/(36/5) = - 5 units
 
tank filled in 2 hours = 8 - 5 = 3 units
 
tank filled in 20 hours = 30 units
 
and
 

Please note that after 20 hours, the remaining capacity = 6 units

Now in the 21st hour, pipe A will work and fill the tank so no need to add time after that.

Time taken by pipe A to fill 6 units = 6/8 = 3/4 hours

So,

Total time taken = 20 + 3/4 = \(20\frac{3}{4}\) hour
Shortcut Trick qImage66c71682996b5810a0ae6e3d

Pipes A and B can fill a tank with water in 30 minutes and 40 minutes, respectively, while pipe C can drain off 51 litres of water per minute. If all the three pipes are opened together, the tank is filled in 90 minutes. What is the capacity (in litres) of the tank?

  1. 900
  2. 864
  3. 720
  4. 1080

Answer (Detailed Solution Below)

Option 4 : 1080

Pipe and Cistern Question 9 Detailed Solution

Download Solution PDF

Given:

Pipes A can fill a tank with water in 30 minutes

Pipes B can fill a tank with water in 40 minutes

Pipe C can drain off 51 litres of water per minute

All the three pipes are opened together, the tank is filled in 90 minutes

Concept used:

LCM method used,

Calculation:

According to the question:

Lcm of (30, 40, 90) = 360

F1 Suhani.K 17-09-21 Savita D1

Efficiency of C = (12 + 9) - 4 = 17 l/min

Which is actually 51 litres/min,

⇒ 17 unit = 51lit

⇒ 360 unit = (51/17) × 360 = 1080 litres

∴ The capacity (in litres) of the tank is 1080 litres.

Both tap M and tap N together can fill a tank in 20/3 hours. If tap M opens for only 4 hours and the remaining tank is filled by tap N for only 9 hours. How many hours to fill the tank by tap N?

  1. 10 hours
  2. 12.5 hours
  3. 25 hours 
  4. 10.5 hours 

Answer (Detailed Solution Below)

Option 2 : 12.5 hours

Pipe and Cistern Question 10 Detailed Solution

Download Solution PDF

Calculation:

According to question

⇒ (M + N) × 20/3 = 4M + 9N

⇒ 20M + 20N = 12M + 27N

⇒ 8M = 7N

⇒ M/N = 7/8

To fill the complete tank by tap N = (4M + 9N)/efficiency of N

To fill the complete tank by tap N = (4 × 7 + 9 × 8)/8 = 100/8 = 25/2

∴ To fill the complete tank by tap N is 12.5 hours 

Two pipes can fill a cistern separately in 20 minutes and 40 minutes respectively and a waste pipe can drain off 35 gallons per minute. If all three pipes are opened, the cistern gets filled in an hour. What is the capacity of the cistern?

  1. 500 gallons
  2. 600 gallons
  3. 750 gallons
  4. 800 gallons

Answer (Detailed Solution Below)

Option 2 : 600 gallons

Pipe and Cistern Question 11 Detailed Solution

Download Solution PDF

Calculation:

Let capacity of cistern be x gallons

Pipe A fills cistern in 20 min

⇒ Cistern filled by pipe A in 1 hour = 3x

Pipe B fills cistern in 40 min

Cistern filled by pipe B in 1 hour = 60/40 = 1.5x

⇒ Water drained by waste pipe in 1 hour = 35 × 60 = 2100 gallons

If all three pipes are connected, Cistern fills in 1 hour

⇒ 3x + 1.5x - 2100 = x

⇒ 4.5x - x = 2100

⇒ 3.5x = 2100

⇒ x = 2100/3.5 = 600  

∴ The correct answer is 600 gallons

Alternate Method Let's denote the capacity of the cistern as C gallons. We then have:

The rate of the first pipe is C/20 gallons per minute.

The rate of the second pipe is C/40 gallons per minute.

The waste pipe drains at a rate of 35 gallons per minute.

When all three pipes are open, the cistern is filled in 60 minutes (1 hour), meaning the net rate is C/60 gallons per minute.

(C/20) + (C/40) - 35 = C/60

6C + 3C - 4200 = 2C

7C = 4200

C = 4200 / 7 = 600

So, the capacity of the cistern is 600 gallons.

Working together, pipes A and B can fill an empty tank in 10 hours. They worked together for 4 hours and then B stopped, and A continued filling the tank till it was full. It took a total of 13 hours to fill the tank. How long would it take A to fill the empty tank alone?

  1. 15 hours
  2. 13 hours
  3. 16 hours
  4. 12 hours

Answer (Detailed Solution Below)

Option 1 : 15 hours

Pipe and Cistern Question 12 Detailed Solution

Download Solution PDF

Calculation:

Working together, pipes A and B can fill an empty tank in 10 hours,

⇒ 1/A + 1/B = 1/10

together they worked for 4 hours and then A continued, and work completed in 13 hrs,

It means A worked for 13 hrs.

⇒ (4/A + 4/B) + 9/A = 1

⇒ 4/10 + 9/A = 1

∴ A = 15 hrs

Alternate Method

Time is taken to fill the tank by A and B = 10 hrs = 100% of total work

A and B worked together for 4 hrs = 40% of total work

So,  6 hours of work remaining = 60% of total work

Work done by A alone = 13 - 4 = 9 hours

60% of work is done by A in 9 hours

100% of work = (9/60) × 100 = 15 hours

∴ The time taken by A to complete work is 15 hours.

Taps P, Q, and R can fill a tank in 20, 25, and 40 hours respectively. Taps Q is kept open for 10 hours, and then tap Q is closed, after that tap P and R are opened. Tap R is closed 9 hours before the tank overflows. How long does it take to fill the tank?

  1. 20 hours
  2. 21 hours
  3. 17 hours
  4. 16 hours

Answer (Detailed Solution Below)

Option 2 : 21 hours

Pipe and Cistern Question 13 Detailed Solution

Download Solution PDF

Given:

Tap P can fill a tank = 20 hours

Tap Q can fill a tank = 25 hours

Tap R can fill a tank = 40 hours

Calculation:

Let the total work be LCM of 20, 25, and 40 = 200 units

⇒ Efficiency of tap P = 200/20 = 10 units

⇒ Efficiency of tap Q = 200/25 = 8 units

⇒ Efficiency of tap R = 200/40 = 5 units

Since the tap Q is kept open for 10 hours,

Work done by tap Q = 10 × 8 = 80 units

∵ Tap R is closed 9 hours before the tank overflows

⇒ Tap P alone worked for 9 hours.

⇒ Work done by tap P alone = 9 × 10 = 90 units

Remaining work = 200 - (80 + 90) = 30 units

The remaining work was done by tap P and tap R together

Time taken by tap P and Tap R to complete the remaining work = 30/(10 + 5) = 30/15 = 2 hours

∴ The total time to fill the tank is (10 + 9 + 2) 21 hours.

Pipe A can fill a tank in 6 hours. Pipe B can fill the same tank in 8 hours. Pipe A, B and C together can fill the same tank in 12 hours. Then which of the following statements is true for pipe C?

  1. It can fill the tank in 4 hours 40 minutes
  2. It can fill the tank in 4 hours 48 minutes
  3. It can empty the tank in 4 hours 48 minutes
  4. It can empty the tank in 4 hours 40 minutes

Answer (Detailed Solution Below)

Option 3 : It can empty the tank in 4 hours 48 minutes

Pipe and Cistern Question 14 Detailed Solution

Download Solution PDF

Given:

Time taken by A to fill tank = 6 hours

Time taken by B to fill tank = 8 hours

Time taken by A, B and, C together to fill the tank = 12 hours

Concept used:

Total work = time × efficiency 

Calculation:

Let the capacity of the tank ( work to be done) be 24x units (LCM of 6, 8, 12)

⇒ The efficiency of pipe A = 24x/6 = 4x units/day

⇒ Efficiency of pipe B = 24x/8 = 3x units/day

⇒ Efficiency of pipe (A + B + C) = 24x/12 = 2x units/day

⇒ Efficiency of pipe C = efficiency of (A + B = C) - efficiency of (A + B)

Efficiency of pipe C = 2x – (4x + 3x) = – 5x units/day

Negative efficiency implies that pipe C is emptying pipe.

⇒ Time taken by pipe C to empty the filled tank = 24x/5x

= 4.8 hours or 4 hrs 48 min

∴ The pipe C will empty the tank in 4 hrs 48 mins.

Pipe A and pipe B running together can fill a cistern in 6 minutes. If B takes 5 minutes more than A to fill it, then the time in which A and B will fill that cistern separately will be, respectively, __________ .

  1. 15 min and 10 min
  2. 15 min and 20 min
  3. 25 min and 20 min
  4. 10 min and 15 min

Answer (Detailed Solution Below)

Option 4 : 10 min and 15 min

Pipe and Cistern Question 15 Detailed Solution

Download Solution PDF

Given:

Pipe A and pipe B running together can fill a cistern in 6 minutes.

B takes 5 minutes more than A to fill it. 

 

Concept used:

Efficiency = (Total work / Total time taken)

Efficiency = work done in a single day 

Calculation:

Let Pipe A takes x minutes

So pipe B takes x+5 minutes

As per the question,

1/x + 1/(x+5) = 1/6

2x + 5 = x(x+5) 1/6

12x + 30 = x2 + 5x

x2 - 7x - 30 = 0

(x+3)(x-10) = 0

So x = 10 

Time taken by B is 10 + 5 = 15 minutes

∴ The correct option is 4

Get Free Access Now
Hot Links: teen patti real teen patti joy 51 bonus real teen patti teen patti lucky