# pipe a can fill a tank in 40 minutes whereas pipe b can empty it in 20 minutes. if both the pipes are opened together what will be the time taken to fill the tank?

### Mohammed

Guys, does anyone know the answer?

get pipe a can fill a tank in 40 minutes whereas pipe b can empty it in 20 minutes. if both the pipes are opened together what will be the time taken to fill the tank? from screen.

## Two pipes A and B can fill a water tank in 20 minutes and 24 minutes, respectively, and the third pipe C can empty at the rate of 3 gallons per minute. If A, B and C opened together, fill the tank in 15 minutes the capacity (in gallons) of the tank is

Click here👆to get an answer to your question ✍️ Two pipes A and B can fill a water tank in 20 minutes and 24 minutes, respectively, and the third pipe C can empty at the rate of 3 gallons per minute. If A, B and C opened together, fill the tank in 15 minutes the capacity (in gallons) of the tank is

Question

## Two pipes A and B can fill a water tank in 20 minutes and 24 minutes, respectively, and the third pipe C can empty at the rate of 3 gallons per minute. If A, B and C opened together, fill the tank in 15 minutes the capacity (in gallons) of the tank is

**A**

## 180

**B**

## 150

**C**

## 120

**D**

## 60

Medium Open in App

Updated on : 2022-09-05

Solution Verified by Toppr

Correct option is C)

Part of the tank filled when all the three pipes are opened in 1 minute =

15 1

Part of the tank filled when (A + B) are opened in 1 minute =

20 1 + 24 1 = 120 6+5 = 120 11

∴ Part of the tank emptied by C in 1 min =

120 11 − 15 1 = 40 1 ∴ Capacity of = 40 1

part of the tank =3 gallons

∴ Capacity of the tank =(3×40) gallons =120 gallons

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## [Solved] Pipe A can fill a tank in 40 minutes and Pipe B can empty th

Given: Pipe A = Takes 40 minutes to fill Pipe B = Takes 60 minutes to empty Formula Used: (1/ t) = (1/ a) - (1/ b) where a is time taken by pipe A to fill

Home Quantitative Aptitude Time and Work Pipe and Cistern

## Question

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## Pipe A can fill a tank in 40 minutes and Pipe B can empty the same tank in 60 minutes. Find the total time taken by A and B together to fill the tank

150 minutes 120 minutes 140 minutes 60 minutes

## Answer (Detailed Solution Below)

Option 2 : 120 minutes

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## Detailed Solution

Download Solution PDF

**Given:**

Pipe A = Takes 40 minutes to fill

Pipe B = Takes 60 minutes to empty

**Formula Used:**

(1/ t) = (1/ a) - (1/ b)

where a is time taken by pipe A to fill the tank and b is time taken by B to empty the tank

**Calculation:**

Here, a = 40 and b = 60,

(1/ t) = (1/ 40) - (1/ 60)

⇒ (1/ t) = (3- 2)/ 120

⇒ (1/ t) = (1/ 120)

**∴ t = 120 minutes**

Alternate Method

**Convert minutes into efficiency**

Take LCM of 40 and 60

LCM (40, 60) = 120

Now, units of time taken by pipe A = 120/ 40

⇒ Units = 3

Units of time taken by pipe B = 120/ 60

⇒ Units = 2

Time taken by tank to fill the whole tank when both pipes are open = 120/ (3 - 2)

⇒ T = 120 minutes

**∴ T = 120 minutes**

Correct answer is option 2

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## More Pipe and Cistern Questions

**Q1.**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?

**Q2.**A pool has 3 taps. The first tap takes 3 days, the second tap takes 2 days, and the third tap takes 18 hours, to fill the pool. All the three taps are opened together. After 8 hours, the second tap is closed. The total time to fill the pool completely will be:

**Q3.**Pipes A and B can fill a tank in 9 hours and 15 hours, respectively. Both pipes were opened at the same time. After some time, it was found that there was a leak at the bottom of the tank which was capable of emptying the fully filled tank in

2212

hours. It was then repaired. If the tank got filled in a total time of 6 hours, then after how much time was the leakage repaired?

**Q4.**A tank has n pipes attached to it, out of which 2 are outlet pipes and the rest are inlet pipes. Each inlet pipe can fill a tank in 10 hours and each outlet pipe can empty the full tank in 15 hours. When all the pipes are opened together then 91

23

% part of the tank is filled in 2

12

hours. What is the value of n?

**Q5.**Pipes A, B and C can fill a tank in 20, 30 and 60 hours, respectively. Pipes A, B and C are opened at 7 a.m., 8 a.m., and 9 a.m., respectively, on the same day. When will the tank be full?

**Q6.**Two pipes A and B can fill a tank in 12 minutes and 24 minutes, respectively, while a third pipe C can empty the full tank in 32 minutes. All the three pipes are opened simultaneously. However, pipe C is closed 2 minutes before the tank is filled. In how much time (in minutes) will the tank be full?

**Q7.**If a water tank is filled

47

part in 8 hours, then what time will be taken in filling the half of the tank?

**Q8.**Two pipes A and B can fill a cistern in

1212

hours and 25 hours, respectively. The pipes were opened simultaneously, and it was found that, due to leakage in the bottom, it took one hour 40 minutes more to fill the cistern. If the cistern is full, in how much time (in hours) will the leak alone empty 70% of the cistern?

**Q9.**Pipes A and B are filling pipes whereas pipe C is an emptying pipe. Pipes A and B together can fill a tank in 30 hours. A, B and C together takes 33

13

% more time than what A and B together take to fill the tank. How much time (in hours) will C alone take to empty the full tank?

**Q10.**A leak in the bottom of a tank can empty the full tank in 9 hours. An inlet pipe fills water at the rate of 5 litres per minute. When the tank is full, the inlet is opened and due to the leak the tank gets empty in 12 hours. The capacity of the tank (in litres) is:

## More Time and Work Questions

**Q1.**If seven persons can build a house in 30 days, how long will it take three persons to build the same house, provided that they all work at the same rate?

**Q2.**A, B and C can complete a work in 12, 16 and 24 days respectively. B and C worked together for 4 days then C left the work and A replaced him. In how many days will the remaining work be completed?

**Q3.**Ram and Rahim together have Rs. 1210. If

13

of Ram's money is equal to

25

of Rahim's amount, then what is the amount (in Rs.) that Rahim has?

**Q4.**P, Q, R can do a piece of work in 40 days, 90 days and 36 days, respectively. P started the work. Q joined him after 7 days. If R joined them after 8 days from the beginning, then for how many days did R work?

## Pipe A can fill a tank in 40 minutes. Pipe B can fill the same tank in 20 minutes. A crack at the bottom of the tank can empty the tank in 120 minutes. If both the pipes are opened simultaneously when the tank is empty and water gets drained through the crack at the bottom, when will the tank be full?

Pipe A can fill a tank in 40 minutes. Pipe B can fill the same tank in 20 minutes. A crack at the bottom of the tank can empty the tank in 120 minutes. If both the pipes are opened simultaneously when the tank is empty and water gets drained through the crack at the bottom, when will the tank be full?

Pipes and Cisterns

## Pipe A can fill a tank in 40 minutes. Pipe B can fill the same tank in 20 minutes. A crack at the bottom of the tank can empty the tank in 120 minutes. If both the pipes are opened simultaneously when the tank is empty and water gets drained through the crack at the bottom, when will the tank be full?

A) 18 minutes B) 15 minutes C) 12 minutes D) 21 minutes Correct Answer: B) 15 minutes

Description for Correct answer:

Pipe A fills 1 40 140

th of the tank every minute. Pipe B fills

1 20 120

th every minute. The crack at the bottom drains

1 120 1120

th of the tank every minute.

Therefore, when both the pipes are opened and the crack is left unchecked,

1 40 + 1 20 = 1 120 140+120=1120

th of the tank gets filled.

That is, 3+6−1 120 = 8 120 = 1 15 3+6−1120=8120=115

th of the tank gets filled every minute.

Hence, the tank will be full in 15 minutes.

Part of solved Pipes and Cisterns questions and answers : >> Aptitude >> Pipes and Cisterns

Comments Similar Questions 1). A pipe can fill 2 3 23

rds of a tank in 16 minutes. How long will it take to fill 3/4ths of the tank?

A). 12 minutes B). 15 minutes C). 18 minutes D). 24 minutes -- View Answer

2). Pipe A can fill a tank at the rate of 35 gallons in 10 minutes. Pipe A will fill a tank that is

x 3 x3

rds empty in 12 minutes. What is the capacity of the tank?

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3). There is a crack at the bottom of a tank. Before the crack appeared, Pipe A could fill the tank in 2 hours. Now it takes half an hour longer. How long will the crack take to empty a full tank when Pipe A is kept closed?

A). 10 hours B). 12 hours C). 15 hours D). 9 hours -- View Answer

4). Pipe A can fill a tank in 14 hours and Pipe B can fill the same tank in 16 hours. Because of a crack at the bottom of the tank, it takes 32 minutes more to fill the empty tank when both the pipes are kept open simultaneously. How long will the crack at the bottom take to drain a full tank if Pipes A and B are kept closed?

A). 108 hours B). 112 hours C). 120 hours D). 130 hours -- View Answer

5). 3 small pumps and a large pump are filling a tank. Each of the three small pumps works at 2/3rd the rate of the large pump. If all 4 pumps work together, they should fill the tank in what fraction of the time that would have taken the large pump alone?

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6). Pipe A which can fill a tank in 20 minutes is kept open for 5 minutes when the tank is empty. Then Pipe B which can fill the tank in 30 minutes is also opened. How long after Pipe A is opened will the tank be full?

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7). Pipe A alone can fill a tank in 8 minutes. Pipe B alone can fill the same tank in 12 minutes. Both the pipes are opened together when the tank is empty. However, Pipe B is closed 3 minutes before the tank is full. In what time did the tank get filled?

A). 6 minutes B). 8 minutes C). 10 minutes D). 12 minutes -- View Answer

8). Pipe A alone can fill a tank in 12 minutes and Pipe B can fill the same tank in 15 minutes. Pipe C which is at the bottom of the tank can drain the tank at the rate of 22 litres/minute. If all three pipes are kept open together when the tank is full, the tank gets emptied in one hour. What is the capacity of the tank?

A). 140Ltrs. B). 132 Ltrs. C). 150 Ltrs. D). 146 Ltrs. -- View Answer

9). Pipe A can fill a tank in 4 minutes. Pipe B can fill the same tank in 8 minutes. Pipe C at the bottom of the tank can drain the tank completely in 6 minutes. If all three pipes are kept open together when the tank is empty and pipe C is shut after 3 minutes, in how many minutes will the tank be full after Pipe C is shut?

A). 3 minutes B). 5 minutes C). 1 minute D). 2 minutes -- View Answer

10). Pipe A fills a tank in 24 minutes. Pipe B can fill the same tank 7 times as fast as Pipe A. If both the pipes are kept open when the tank is empty, when will the tank be full?

A). 5 minutes B). 2 minutes C). 4 minutes D). 3 minutes -- View Answer

Guys, does anyone know the answer?