A. 4.5 hrs
B. 5 hrs
C. 6.5 hrs
D. 7.2 hrs
Explanation:
Net part filled in 1 hour = (1/4 – 1/9) = 5/36
The cistern will be filled in 36/5 hrs i.e., 7.2 hrs.
Related Mcqs:
- A cistern can be filled by a tap in 4 hours while it can be emptied by another tap in 9 hours. If both the taps are opened simultaneously, then after how much time will the cistern get filled?
A. 4.5 hrs
B. 5 hrs
C. 6.5 hrs
D. 7.2 hrs - A cistern has two taps which fill it in 12 min. and 15 min.respectively There is one outlet pipe in the cistern. When all the taps & pipe are opened, the empty cistern is full in 20 min. How long will the waste pipe (outlet) take to empty the full cistern ?
A. 10 min
B. 20 min
C. 30 min
D. 40 min - A cistern has a leak which would empty the cistern in 20 minutes. A tap is turned on which admits 4 liters a minute into the cistern, and it is emptied in 24 minutes. How many liters does the cistern hold?
A. 480 liters
B. 600 liters
C. 720 liters
D. 800 liters - A cistern is filled by a tap in 3 1/2 hours. Due to leak in the bottom of the cistern, it takes half an hour longer to fill the cistern. If the cistern is full how long will it take the leak to empty it?
A. 7 hours
B. 8 hours
C. 14 hours
D. 28 hours - One top can fill a cistern in 2 hours and another can empty the cistern in 3 hours. How long will they take to fill the cistern if both the taps are opened?
A. 5 Hours
B. 6 Hours
C. 7 Hours
D. 8 Hours - Two pipes A and B can separately fill a cistern in 60 min and 75 min respectively. There is a third pipe in the bottom of the cistern to empty it. If all the three pipes are simultaneously opened, then the cistern is full in 50 min. In how much time, the third pipe alone can empty the cistern?
A. 90 min
B. 100 min
C. 110 min
D. 120 min - A top can fill a cistern in 8 hours and another can empty it in 16 hours. If both the taps are opened simultaneously the time (in hours) to fill the tank is
A. 8
B. 10
C. 16
D. 24 - A pipe can fill a cistern in 20 minutes whereas the cistern when fill can be emptied by a leak in 28 minutes. When both pipes are opened, find when the cistern will be full?
A. 60 min
B. 80 min
C. 70 min
D. 48 min - 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 cistern. How much time will be taken by A to fill the cistern separately?
A. 1 hr
B. 2 hrs
C. 6 hrs
D. 8 hrs - A tap can fill a tank in 6 hours. After half the tank is filled three more similar taps are opened. What is the total time taken to fill the tank completely?
A. 3 hrs 15 min
B. 3 hrs 45 min
C. 4 hrs
D. 4 hrs 15 min