105 + Mcqs in Pipes and Cistern in Aptitude Page 1 McqOptions

1.	A pump can fill a tank with water in 2 hours. Because of a leak, it took 2 hours to fill the tank. The leak can drain all the water of the tank in:
A.	7 hours
B.	8 hours
C.	14 hours
Answer» E.

Discussion

2.	Two pipes A and B can fill a cistern in 37 minutes and 45 minutes respectively. Both pipes are opened. The cistern will be filled in just half an hour, if the B is turned off after:
A.	5 min.
B.	9 min.
C.	10 min.
D.	15 min.
Answer» C. 10 min.

Discussion

3.	A pump can fill a tank with water in 2 hours. Because of a leak, it took 2 hours to fill the tank. The leak can drain all the water of the tank in:
A.	7 hours
B.	8 hours
C.	14 hours
Answer» E.

Discussion

4.	Two pipes A and B can fill a cistern in 37 minutes and 45 minutes respectively. Both pipes are opened. The cistern will be filled in just half an hour, if the B is turned off after:
A.	5 min.
B.	9 min.
C.	10 min.
D.	15 min.
Answer» C. 10 min.

Discussion

5.	Pipe A can fill an empty tank in 6 hours and pipe B in 8 hours. If both the pipes are opened and after 2 hours pipe. A is closed, how much time B will take to fill the remaining tank?
A.
B.
C.
Answer» E.

Discussion

6.	An empty tank can be filled by pipe A in 4 hours and by pipe B in 6 hours. If the two pipes are opened for 1 hour each alternately with first opening pipe A, then the tank will be filled in
A.
B.
Answer» D.

Discussion

7.	Pipe A can fill a tank in 4 hours and pipe B can fill it in 6 hours. If they are opened on alternate hours and if pipe A is opened first, in how many hours, the tank shall be full ?
A.
B.
C.
Answer» E.

Discussion

8.	A tank has two pipes. The first pipe can fill it in 4 hours and the second can empty it in 16 hours. If two pipes be opened together at a time, then the tank will be filled in
A.	10 hours
B.
C.	6 hours
D.
Answer» E.

Discussion

9.

Two pipes A and B can fill a cistern in 37 1 minutes and 45 minutes respectively. Both
2

pipes are opened.The cistern will be filled just in half an hour, if the pipe B is turned off after :

A.

15 minutes

B.

10 minutes

C.

D.

5 minutes

E.

9 minutes

Answer» E. 9 minutes

Discussion

10.

A pipe can fill a tank with water in 3 hours. Due to leakage in bottom, it takes
3 1 hours to fill it . In what time the leak will empty the fully filled tank ?
2

A.

12 hours

B.

C.

21 hours

D.

E.

Answer» C. 21 hours

Discussion

11.

A pump can fill a tank with water in 2 hours. Because of a leak in the tank it was
taking 2 1 hours to fill the tank. The leak can drain all the water off the tank in :
3

A.

8 hours

B.

C.

7 hours

D.

14 hours

Answer» E.

Discussion

12.	Three taps A, B and C can fill a tank in 12, 15 and 20 hours respectively. If A is open all the time and B and C are open for one hour each alternatively, the tank will be full in :
A.	6 hours
B.
C.	7 hours
D.
Answer» D.

Discussion

13.	Two pipes can fill a tank in 15 hours and 20 hours respectively, while the third can empty it in 30 hours. If all the pipes are opened simultaneously, the empty tank will be filled in
A.	10 hours
B.
C.	12 hours
D.
E.	15 hours
Answer» C. 12 hours

Discussion

14.	Two pipes A and B can fill a tank in 15 hours and 20 hours respectively while a third pipe C can empty the full tank in 25 hours. All the three pipes are opened in the beginning. After 10 hours, C is closed. The time taken to fill the tank is ?
A.	12 hours
B.	13
C.	/
D.	16 hours
E.	18 hours
Answer» B. 13

Discussion

15.	A cistern can be filled with water by a pipe in 5 hours and it can be emptied by a second pipe in 4 hours. If both the pipes are opened when the cistern is full, the time in which it will be emptied is :
A.	9 hours
B.
C.	18 hours
D.
E.	20 hours
Answer» D.

Discussion

16.	There are 7 pipes attached with a tank out of which some are inlets and some are outlets. Every inlet can fill the tank in 10 h and every outlet can empty the tank in 15 h. When all the pipes are opened simultaneously, the tank is filled up in 2⁸/₁₁ h. Find the numbers of inlets and outlets. ?
A.	5, 2
B.	6,1
C.	4,3
D.	3,4
Answer» B. 6,1

Discussion

17.	A large tanker can be filled by two pipes A and B in 60 minutes and 40 minutes respectively. How many minutes will it take to fill the tanker from empty state if B is used for half the time and A and B fill it together for the other half?
A.	15 min
B.	20 min
C.	27.5 min
D.	30 min
Answer» E.

Discussion

18.	Three pipes A, B and C can fill a tank in 6 hours. After working at it together for 2 hours, C is closed and A and B can fill the remaining part in 7 hours. The number of hours taken by C alone to fill the tank is:
A.	10
B.	12
C.	14
D.	16
Answer» D. 16

Discussion

19.	A tank is filled in 5 hours by three pipes A, B and C. The pipe C is twice as fast as B and B is twice as fast as A. How much time will pipe A alone take to fill the tank?
A.	20 hours
B.	25 hours
C.	35 hours
D.	Cannot be determined
E.	None of these
Answer» D. Cannot be determined

Discussion

20.	Two pipes A and B together can fill a cistern in 4 hours. Had they been opened separately, then B would have taken 6 hours more than A to fill the cistern. How much time will be taken by A to fill the cistern separately?
A.	1 hour
B.	2 hours
C.	6 hours
D.	8 hours
Answer» D. 8 hours

Discussion

21.	Two pipes A and B can fill a tank in 20 and 30 minutes respectively. If both the pipes are used together, then how long will it take to fill the tank?
A.	12 min
B.	15 min
C.	25 min
D.	50 min
Answer» B. 15 min

Discussion

22.	Two pipes A and B can fill a tank in 15 minutes and 20 minutes respectively. Both the pipes are opened together but after 4 minutes, pipe A is turned off. What is the total time required to fill the tank?
A.	10 min. 20 sec.
B.	11 min. 45 sec.
C.	12 min. 30 sec.
D.	14 min. 40 sec.
Answer» E.

Discussion

23.	Two pipes A and B can fill a cistern in 37 minutes and 45 minutes respectively. Both pipes are opened. The cistern will be filled in just half an hour, if the B is turned off after:
A.	5 min.
B.	9 min.
C.	10 min.
D.	15 min.
Answer» C. 10 min.

Discussion

24.	A pump can fill a tank with water in 2 hours. Because of a leak, it took 2 hours to fill the tank. The leak can drain all the water of the tank in:
A.	<table class="ga-tbl-answer" cellpadding="0" cellspacing="0"> <tbody><tr class="ga-tr-divident" align="center"> <td class="ga-td-line" rowspan="2">4</td> <td class="ga-td-divident">1</td> <td class="ga-td-line-lpad" rowspan="2">hours</td> </tr> <tr class="ga-tr-divisor" align="center"> <td class="ga-td-divisor">3</td> </tr> </tbody></table>
B.	7 hours
C.	8 hours
D.	14 hours
Answer» E.

Discussion

25.	A tank is filled by three pipes with uniform flow. The first two pipes operating simultaneously fill the tank in the same time during which the tank is filled by the third pipe alone. The second pipe fills the tank 5 hours faster than the first pipe and 4 hours slower than the third pipe. The time required by the first pipe is:
A.	6 hours
B.	10 hours
C.	15 hours
D.	30 hours
Answer» D. 30 hours

Discussion

26.	One pipe can fill a tank three times as fast as another pipe. If together the two pipes can fill the tank in 36 minutes, then the slower pipe alone will be able to fill the tank in:
A.	81 min.
B.	108 min.
C.	144 min.
D.	192 min.
Answer» D. 192 min.

Discussion

27.

How long will it take to empty the tank if both the inlet pipe A and the outlet pipe B are opened simultaneously?
I.
A can fill the tank in 16 minutes.
II.
B can empty the full tank in 8 minutes.

A.

I alone sufficient while II alone not sufficient to answer

B.

II alone sufficient while I alone not sufficient to answer

C.

Either I or II alone sufficient to answer

D.

Both I and II are not sufficient to answer

E.

Both I and II are necessary to answer

Answer» F.

Discussion

28.

How much time will the leak take to empty the full cistern?
I.
The cistern is normally filled in 9 hours.
II.
It takes one hour more than the usual time to fill the cistern because of la leak in the bottom.

A.

I alone sufficient while II alone not sufficient to answer

B.

II alone sufficient while I alone not sufficient to answer

C.

Either I or II alone sufficient to answer

D.

Both I and II are not sufficient to answer

E.

Both I and II are necessary to answer

Answer» F.

Discussion

29.

If both the pipes are opened, how many hours will be taken to fill the tank?
I.
The capacity of the tank is 400 litres.
II.
The pipe A fills the tank in 4 hours.
III.
The pipe B fills the tank in 6 hours.

A.

Only I and II

B.

Only II and III

C.

All I, II and III

D.

Any two of the three

E.

Even with all the three statements, answer cannot be given.

Answer» C. All I, II and III

Discussion

30.	Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 3 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank is:
A.	60 gallons
B.	100 gallons
C.	120 gallons
D.	180 gallons
Answer» D. 180 gallons

Discussion

31.	Two pipes A and B can fill a tank in 24 and 32 min, respectively. If both the pipes are opened together, after how much time pipe B should be closed so that the tank is full in 9 min?
A.	40 min
B.	30 min
C.	10 min
D.	20 min
Answer» E.

Discussion

32.	A pipe can fill a cistern in 12 min and another pipe can fill it in 15 min, but a third pipe can empty it in 6 min. The first two pipes are kept open 5 min in the beginning and then the third pipe is also opened.Time taken to empty the cistern is ?
A.	38 min
B.	22 min
C.	42 min
D.	45 min
Answer» E.

Discussion

33.	A cistern has two taps which fill it in 12 min. and 15 min. respectively. There is also a waste pipe in the cistern. When all the pipes are opened the empty cistern is full in 20 min. how long will the waste pipe take to empty a full cistern ?
A.	8 min.
B.	10 min.
C.	12 min.
D.	16 min.
Answer» C. 12 min.

Discussion

34.	Two taps can separately fill a cistern in 10 minutes and 15 minutes respectively and when the waste pipe is open, they can together fill it in 18 minutes. The waste pipe can empty the full cistern in ?
A.	7 minutes
B.	9 minutes
C.	13 minutes
D.	23 minutes
Answer» C. 13 minutes

Discussion

35.	A cistern has 3 pipes A, B and C, A and B can fill it in 2 and 3 hours respectively. C is a waste pipe. If all the 3 pipes be opened at once, 7/24 of the cistern will be filled up in 30 minutes. In what time can C empty the full cistern ?
A.	3 hours
B.	4 hours
C.	5 hours
D.	6 hours
Answer» C. 5 hours

Discussion

36.	Three pipes A, B and C can fill a cistern in 10 hours, 12 hours and 15 hours respectively. First A was opened. After 1 hour, B was opened and after 2 hours from the start of A, C also opened . Find the time in which the cistern is just full ?
A.	2 hrs.
B.	4 hrs.
C.	2 hrs. 52 min.
D.	4 hrs. 52 min.
Answer» E.

Discussion

37.	If two pipes function together, the tank will be filled in 12 h . One pipe fills the tank in 10 h faster than the other. How many hours does the faster pipe take to fill up the tank?
A.	20 h
B.	60 h
C.	15 h
D.	25 h
Answer» B. 60 h

Discussion

38.	A pipe P can fill a tank in 12 min and another pipe R can fill it in 15 min. But, the 3rd pipe M can empty it in 6 min. The 1st two pipes P and R are kept open for double the 2.5 min in beginning and then the 3rd pipe is also opened. In what time is the tank emptied?
A.	30 min
B.	25 min
C.	45 min
D.	35 min
Answer» D. 35 min

Discussion

39.	Three pipes A, B and C can fill a tank in 30 min, 20 min and 10 min, respectively. When the tank is empty, all the three pipes are opened. If A, B and C discharge chemical solution P, Q and R respectively, then the part of solution R in the liquid in the tank after 3 min is ?
A.	8/11
B.	5/11
C.	6/11
D.	7/11
Answer» D. 7/11

Discussion

40.	There are 7 pipes attached with a tank out of which some are inlets and some are outlets. Every inlet can fill the tank in 10 h and every outlet can empty the tank in 15 h. When all the pipes are opened simultaneously, the tank is filled up in 2
A.	5, 2
B.	6,1
C.	4,3
D.	3,4
Answer» B. 6,1

Discussion

41.	Capacity of tap B is 80% more than that of A. If both the taps are opened simultaneously, they take 45 h to fill the tank. How long will B take to fill the tank alone?
A.	72 h
B.	48 h
C.	66 h
D.	70 h
Answer» E.

Discussion

42.	Three pipes A, B and C can fill a cistern in 6 hours. After working at it together for 2 hours, C is closed and A and B can fill it in 7 hours. The time taken by C alone to fill the cistern is ?
A.	10 hours
B.	12 hours
C.	14 hours
D.	16 hours
Answer» D. 16 hours

Discussion

43.	A tank is filled by a pipe A in 32 minutes and pipe B in 36 minutes. When full, it in can be emptied by a pipe C in 20 minutes. If all the three pipes are opened simultaneously, half of the tank will be filled in ?
A.	16 minutes
B.	24 minutes
C.	48 minutes
D.	None of these
Answer» E.

Discussion

44.	If two function simultaneously, the reservoir will be filled in 12 hours. One pipe fills the reservoir 10 hours faster than the other. How many hours does the faster pipe take to fill the reservoir ?
A.	25 hours
B.	28 hours
C.	30 hours
D.	35 hours
Answer» D. 35 hours

Discussion

45.	A cistern which could be filled in 9 hours takes one hour more to be filled owing to a leak in its bottom. If the cistern is full, in what time will the leak empty it ?
A.	80 hours
B.	85 hours
C.	90 hours
D.	95 hours
Answer» D. 95 hours

Discussion

46.	Three taps A, B and C fill a tank in 20 min, 15 min and 12 min, respectively. If all the taps are opened simultaneously, how long will they take to fill 40% of the tank?
A.	1 min
B.	2 min
C.	3 min
D.	4 min
Answer» C. 3 min

Discussion

47.	A tank has a leak which would empty it in 8 h. A tap is turned on which admits 3 L a min into the tank and it is now emptied in 12 h. How many litres does the tank hold?
A.	4320 L
B.	4000 L
C.	2250 L
D.	4120 L
Answer» B. 4000 L

Discussion

48.	Two pipes A and B can fill a cistern in 15 and 20, respectively. Both the pipes are opened together, but after 2 min, pipe A is turned off. What is the total time required to fill the tank?
A.	46/3 min
B.	52/3 min
C.	43/3 min
D.	41/3
Answer» C. 43/3 min

Discussion

49.	Inlet A is four times faster than inlet B to fill a tank. If A alone can fill it in 15 min, how long will it take if both the pipes are opened together?
A.	10 min
B.	12 min
C.	15 min
D.	14 min
Answer» C. 15 min

Discussion

50.	A tap having diameter 'd' empty a tank in 40 min. How long another tap having diameter '2d' take to empty the same tank?
A.	5 min
B.	20 min
C.	10 min
D.	80 min
Answer» C. 10 min

Discussion

Explore topic-wise MCQs in Aptitude.

A pump can fill a tank with water in 2 hours. Because of a leak, it took 2 hours to fill the tank. The leak can drain all the water of the tank in:

Two pipes A and B can fill a cistern in 37 minutes and 45 minutes respectively. Both pipes are opened. The cistern will be filled in just half an hour, if the B is turned off after:

A pump can fill a tank with water in 2 hours. Because of a leak, it took 2 hours to fill the tank. The leak can drain all the water of the tank in:

Two pipes A and B can fill a cistern in 37 minutes and 45 minutes respectively. Both pipes are opened. The cistern will be filled in just half an hour, if the B is turned off after:

Pipe A can fill an empty tank in 6 hours and pipe B in 8 hours. If both the pipes are opened and after 2 hours pipe. A is closed, how much time B will take to fill the remaining tank?

An empty tank can be filled by pipe A in 4 hours and by pipe B in 6 hours. If the two pipes are opened for 1 hour each alternately with first opening pipe A, then the tank will be filled in

Pipe A can fill a tank in 4 hours and pipe B can fill it in 6 hours. If they are opened on alternate hours and if pipe A is opened first, in how many hours, the tank shall be full ?

A tank has two pipes. The first pipe can fill it in 4 hours and the second can empty it in 16 hours. If two pipes be opened together at a time, then the tank will be filled in

Two pipes A and B can fill a cistern in 371 minutes and 45 minutes respectively. Both 2pipes are opened.The cistern will be filled just in half an hour, if the pipe B is turned off after :

A pipe can fill a tank with water in 3 hours. Due to leakage in bottom, it takes 31 hours to fill it . In what time the leak will empty the fully filled tank ? 2

A pump can fill a tank with water in 2 hours. Because of a leak in the tank it was taking 21 hours to fill the tank. The leak can drain all the water off the tank in : 3

Three taps A, B and C can fill a tank in 12, 15 and 20 hours respectively. If A is open all the time and B and C are open for one hour each alternatively, the tank will be full in :

Two pipes can fill a tank in 15 hours and 20 hours respectively, while the third can empty it in 30 hours. If all the pipes are opened simultaneously, the empty tank will be filled in

Two pipes A and B can fill a tank in 15 hours and 20 hours respectively while a third pipe C can empty the full tank in 25 hours. All the three pipes are opened in the beginning. After 10 hours, C is closed. The time taken to fill the tank is ?

A cistern can be filled with water by a pipe in 5 hours and it can be emptied by a second pipe in 4 hours. If both the pipes are opened when the cistern is full, the time in which it will be emptied is :

There are 7 pipes attached with a tank out of which some are inlets and some are outlets. Every inlet can fill the tank in 10 h and every outlet can empty the tank in 15 h. When all the pipes are opened simultaneously, the tank is filled up in 28/11 h. Find the numbers of inlets and outlets. ?

A large tanker can be filled by two pipes A and B in 60 minutes and 40 minutes respectively. How many minutes will it take to fill the tanker from empty state if B is used for half the time and A and B fill it together for the other half?

Three pipes A, B and C can fill a tank in 6 hours. After working at it together for 2 hours, C is closed and A and B can fill the remaining part in 7 hours. The number of hours taken by C alone to fill the tank is:

A tank is filled in 5 hours by three pipes A, B and C. The pipe C is twice as fast as B and B is twice as fast as A. How much time will pipe A alone take to fill the tank?

Two pipes A and B together can fill a cistern in 4 hours. Had they been opened separately, then B would have taken 6 hours more than A to fill the cistern. How much time will be taken by A to fill the cistern separately?

Two pipes A and B can fill a tank in 20 and 30 minutes respectively. If both the pipes are used together, then how long will it take to fill the tank?

Two pipes A and B can fill a tank in 15 minutes and 20 minutes respectively. Both the pipes are opened together but after 4 minutes, pipe A is turned off. What is the total time required to fill the tank?

Two pipes A and B can fill a cistern in 37 minutes and 45 minutes respectively. Both pipes are opened. The cistern will be filled in just half an hour, if the B is turned off after:

A pump can fill a tank with water in 2 hours. Because of a leak, it took 2 hours to fill the tank. The leak can drain all the water of the tank in:

One pipe can fill a tank three times as fast as another pipe. If together the two pipes can fill the tank in 36 minutes, then the slower pipe alone will be able to fill the tank in:

How long will it take to empty the tank if both the inlet pipe A and the outlet pipe B are opened simultaneously? I. A can fill the tank in 16 minutes. II. B can empty the full tank in 8 minutes.

How much time will the leak take to empty the full cistern? I. The cistern is normally filled in 9 hours. II. It takes one hour more than the usual time to fill the cistern because of la leak in the bottom.

If both the pipes are opened, how many hours will be taken to fill the tank? I. The capacity of the tank is 400 litres. II. The pipe A fills the tank in 4 hours. III. The pipe B fills the tank in 6 hours.

Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 3 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank is:

Two pipes A and B can fill a tank in 24 and 32 min, respectively. If both the pipes are opened together, after how much time pipe B should be closed so that the tank is full in 9 min?

A pipe can fill a cistern in 12 min and another pipe can fill it in 15 min, but a third pipe can empty it in 6 min. The first two pipes are kept open 5 min in the beginning and then the third pipe is also opened.Time taken to empty the cistern is ?

A cistern has two taps which fill it in 12 min. and 15 min. respectively. There is also a waste pipe in the cistern. When all the pipes are opened the empty cistern is full in 20 min. how long will the waste pipe take to empty a full cistern ?

Two taps can separately fill a cistern in 10 minutes and 15 minutes respectively and when the waste pipe is open, they can together fill it in 18 minutes. The waste pipe can empty the full cistern in ?

A cistern has 3 pipes A, B and C, A and B can fill it in 2 and 3 hours respectively. C is a waste pipe. If all the 3 pipes be opened at once, 7/24 of the cistern will be filled up in 30 minutes. In what time can C empty the full cistern ?

Three pipes A, B and C can fill a cistern in 10 hours, 12 hours and 15 hours respectively. First A was opened. After 1 hour, B was opened and after 2 hours from the start of A, C also opened . Find the time in which the cistern is just full ?

If two pipes function together, the tank will be filled in 12 h . One pipe fills the tank in 10 h faster than the other. How many hours does the faster pipe take to fill up the tank?

A pipe P can fill a tank in 12 min and another pipe R can fill it in 15 min. But, the 3rd pipe M can empty it in 6 min. The 1st two pipes P and R are kept open for double the 2.5 min in beginning and then the 3rd pipe is also opened. In what time is the tank emptied?

Three pipes A, B and C can fill a tank in 30 min, 20 min and 10 min, respectively. When the tank is empty, all the three pipes are opened. If A, B and C discharge chemical solution P, Q and R respectively, then the part of solution R in the liquid in the tank after 3 min is ?

There are 7 pipes attached with a tank out of which some are inlets and some are outlets. Every inlet can fill the tank in 10 h and every outlet can empty the tank in 15 h. When all the pipes are opened simultaneously, the tank is filled up in 2

Capacity of tap B is 80% more than that of A. If both the taps are opened simultaneously, they take 45 h to fill the tank. How long will B take to fill the tank alone?

Three pipes A, B and C can fill a cistern in 6 hours. After working at it together for 2 hours, C is closed and A and B can fill it in 7 hours. The time taken by C alone to fill the cistern is ?

A tank is filled by a pipe A in 32 minutes and pipe B in 36 minutes. When full, it in can be emptied by a pipe C in 20 minutes. If all the three pipes are opened simultaneously, half of the tank will be filled in ?

If two function simultaneously, the reservoir will be filled in 12 hours. One pipe fills the reservoir 10 hours faster than the other. How many hours does the faster pipe take to fill the reservoir ?

A cistern which could be filled in 9 hours takes one hour more to be filled owing to a leak in its bottom. If the cistern is full, in what time will the leak empty it ?

Three taps A, B and C fill a tank in 20 min, 15 min and 12 min, respectively. If all the taps are opened simultaneously, how long will they take to fill 40% of the tank?

A tank has a leak which would empty it in 8 h. A tap is turned on which admits 3 L a min into the tank and it is now emptied in 12 h. How many litres does the tank hold?

Two pipes A and B can fill a cistern in 15 and 20, respectively. Both the pipes are opened together, but after 2 min, pipe A is turned off. What is the total time required to fill the tank?

Inlet A is four times faster than inlet B to fill a tank. If A alone can fill it in 15 min, how long will it take if both the pipes are opened together?

A tap having diameter 'd' empty a tank in 40 min. How long another tap having diameter '2d' take to empty the same tank?

Two pipes A and B can fill a cistern in 37 1 minutes and 45 minutes respectively. Both
2

pipes are opened.The cistern will be filled just in half an hour, if the pipe B is turned off after :

A pipe can fill a tank with water in 3 hours. Due to leakage in bottom, it takes
3 1 hours to fill it . In what time the leak will empty the fully filled tank ?
2

A pump can fill a tank with water in 2 hours. Because of a leak in the tank it was
taking 2 1 hours to fill the tank. The leak can drain all the water off the tank in :
3

How long will it take to empty the tank if both the inlet pipe A and the outlet pipe B are opened simultaneously?
I.
A can fill the tank in 16 minutes.
II.
B can empty the full tank in 8 minutes.

How much time will the leak take to empty the full cistern?
I.
The cistern is normally filled in 9 hours.
II.
It takes one hour more than the usual time to fill the cistern because of la leak in the bottom.

If both the pipes are opened, how many hours will be taken to fill the tank?
I.
The capacity of the tank is 400 litres.
II.
The pipe A fills the tank in 4 hours.
III.
The pipe B fills the tank in 6 hours.