Problem based on pipes and cisterns
Q.1) 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 it will take to fill the tank?
Ans: 12 minutes
Q.2) A water tank is two-fifth full. Pipe A can fill a tank in 10 minutes and pipe B can empty in 6 minutes. If both the pipes are open, how long will it take to empty or fill the tank completely?
Ans: 6 minutes
Q.3) Pipes A and B can fill a tank in 5 hours and 6 hours respectively. Pipe C can empty it in 12 hours. If all the three pipes are opened together, then the tank will be filled in.
Ans: 60/17 hours
Q.4) 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 liters 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 liters) is-
Ans: 5760 liters
Q.5) A cistern can be filled in 9 hours but due to a leak at its bottom it takes 10 hours. If the cistern is full, then the time that the leak will take to make it empty will be?
Ans: 90 hours
Q.6) A and B can do a piece of work in 45 days and 40 days respectively. They began to do the work together but A leaves after some days and then B completed the remaining work in 23 days. The number of days after which A left the work was-
Ans: 9 days.
Q.7) 39 persons can repair a road in 12 days, working 5 hours a day. In how many days will 30 persons, working 6 hours a day, complete the work?
Ans: 13 days
Q.8) Pipes A and B can fill a tank in 12 min and 16 min respectively. Both are kept open for 'n' min and then B is closed and A fills the rest of the tank in 5 min. The time 'n' after which B was closed is-
Ans: 4 minutes
Q.9) Pipe A can fill a tank in 'a' hours. On account of a leak at the bottom of the tank it takes thrice as long to fill the tank. How long will the leaks at the bottom of the tank take to empty a full tank, when pipe A is kept closed?
Ans: 3a/2 hours
Q.10) One fill pipe ‘A’ is 3 times faster than second fill pipe ‘B’ and takes 32 minutes less than the fill pipe ‘B’. When will the cistern be full if both pipes are opened together?
Ans: 12 minutes