A pipe A can fill a cistern in 12 hours, while pipe B can fill it in 8 hours. In how much time will the cistern be filled, if both pipes A and B are opened together?
Given:
Pipe A fills cistern in 12 hours.
Pipe B fills cistern in 8 hours.
Formula Used:
Work rate =
Time
Solution:
Work rate of A = per hour.
Work rate of B = per hour.
Combined work rate =
Time taken together:
T =
Convert 0.8 hours into minutes:
0.8 × 60 = 48 minutes
The cistern will be filled in 4 hours 48 minutes
Alternate method
LCM of 12 and 8 = 24 units
A does 2 units/hour, B does 3 units/hour
Together = 5 units/hour.
Time == 4.8 hours = 4h 48m.
English
100 Questions
100 Marks
90 Mins English English100 Questions100 Marks90 Mins English English100 Questions100 Marks90 Mins EnglishTwo pipes A and B can fill a tank in 28 hours and 21 hours, respectively. If both the pipes are opened simultaneously, then the time taken (in hours) to fill the tank is:
Two pipes, P and Q, together can fill a tank in 5 hours. If pipe P alone can fill the tank in 10 hours, then how much time (in hours) will pipe Q alone take to fill the tank?
Pipes A and B can fill a tank in 12 hours and 18 hours, respectively. Pipe C is an emptying pipe. When all the three pipes are opened together for 8 hours, then 26/45 part of the tank is filled up. What part of the tank will be filled up by A and C together in 9 hours?
Pipe A can fill a tank in 13 hours, pipe B can fill the same tank in 26 hours and pipe C can fill the same tank in 17 hours. The time taken by them to fill the same tank if they operate together is:
A leaking tap drips at the rate of 150 mL per hour. Water wasted in a day will be
Pipes P and Q can fill a tank in 18 hours and 27 hours respectively. Pipe R is an emptying pipe. When the tank is empty, P and Q are opened together for 6 hours and then both are closed and R is opened. The tank is now emptied in 30 hours. In how many hours can P and R together fill half the tank?
Two pipes A and B can fill a tank in 18 and 24 minutes respectively. After both are opened together for 6 minutes, the rate of pipe A becomes half, and pipe B becomes double its original. In how many more minutes will the tank be full?
Pipe A can fill a tank in 15 hours, pipe B can fill the same tank in 27 hours and pipe C can fill the same tank in 10 hours. The time taken by them to fill the same tank if they operate together is::
A pipe can fill a water tank in 36 minutes, and another can fill it in 48 minutes, but a third pipe can empty it in 18 minutes. The first two pipes are kept open for 16 minutes at the beginning, and then the third pipe is also opened. How long does it take to empty the tank?
Pipe P can fill 3/4 part of a tank in 15 hours, and pipe Q can fill 5/6 part of the same tank in 25 hours. Both P and Q were kept open for 2 hours, then both were closed. Pipe R alone was then opened and it emptied the water in the tank in 5 hours. Pipes P, Q and R together can fill the empty tank in:
Suggested Test Series
Suggested Test Series
