21. Two pipes A and B can fill a
cistern in 12 minutes and 16 minutes respectively. If both the pipes are opened together, then after how
much time B should be closed so that the tank is full in 9 minutes ?
A.3 min and 30 sec. B.4 min and 30 sec.
C.4 min. D.4 min
77 sec.
22.
|
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
|
|
23. A cistern can be filled in 9 hours but it takes 10 hours due
to in its bottom. If the cistern is full, then the time that the leak
will take to empty it, is
A.60 hrs B.80 hrs
C.70 hrs D.90 hrs
24.
|
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.
|
|
25. A tank can be filled by a tap in 20 minutes and by another tap
in 6O minutes. Both the taps are kept open for 10 minutes and then the first
tap is shut off. After this, the tank will be completely filled in
A.10 miii. B.15 mm.
C.12 mm. D.20 mm.
26. TapsA and B can fiJi a bucket in 12 minutes and 15 minutes respectively.
If both are opened and A is closed after 3 minutes, how much further time would
it take for B to fill the bucket
A.7 nun. 45 sec. B.8 mm. 5
sec.
C.7 mm. 15 sec. D.8 mm.
15 sec.
27. A tap can fill a tank in 16 minutes and another can empty it
in 8 minutes. If the tank is already half full and both the tanks are oped
together, the tank will be:
A.filled in 12 mm. B.filled in 8 mm,
C.emptied in 12 mm. D.emptied
in 8 mm.
28.
|
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
|
|
|
|
29. Bucket P has thrice the capacity as bucket Q It takes 60 turns
for bucket P to fill the empty drum. How many turns it wifi take for both the
buckets P and Q, having each turn together to fill the empty drum?.
A.30 B.45
C.40 D.90
30. A leak in the bottom of a tank can empty the full tank in 6
hours. An inlet pipe fills water at the rate of 4 litres a minute. When the
tank is full, the inlet is opened and due to the leak the tank is empty in 8
hours. The capacity of the tank (in litres) is
A.5260 B.5846
C.5760 D.6970
