A. 7 hours
B. 8 hours
C. 14 hours
D. 28 hours
Explanation:
2/7 – 1/x = 1/4
x = 28
Related Mcqs:
- A cistern is normally filled in 8 hours but takes two hours longer to fill because of a leak in its bottom. If the cistern is full, the leak will empty it in?
A. 16 hrs
B. 20 hrs
C. 40 hrs
D. 25 hrs - A cistern is normally filled in 8 hours but takes two hours longer to fill because of a leak in its bottom. If the cistern is full the leak will empty it in.
A. 16 hrs
B. 20 hrs
C. 25 hrs
D. 40 hrs - 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. 45 hrs
B. 60 hrs
C. 75 hrs
D. 90 hrs - Pipe A can fill a tank in 6 hours. Due to a leak at the bottom, it takes 9 hours for the pipe A to fill the tank. In what time can the leak alone empty the full tank?
A. 16 hours
B. 15 hours
C. 18 hours
D. 17 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 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 - Two pipes A and B can separately fill a cistern in 10 and 15 minutes respectively. A person opens both the pipes together when the cistern should have been was full he finds the waste pipe open. He then closes the waste pipe and in another 4 minutes the cistern was full. In what time can the waste pipe empty the cistern when fill?
A. 7 min
B. 8 min
C. 9 min
D. 10 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 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 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