31). Pipe A fills a tank of capacity 700 liters at the rate of 40 liters a minute. Another pipe, pipe B, fills the same tank at the rate of 30 liters a minute. A pipe at the bottom of the tank drains the tank at the rate of 20 liters a minute. If pipe A is kept open for a minute and then closed and pipe B is kept open for a minute and then closed and then pipe C is kept open for a minute and then closed and the cycle repeated, when will the tank be full?
A). 46 minutes 40 seconds 
B). 52 minutes 15 seconds 
C). 40 minutes 20 seconds 
D). 36 minutes 50 seconds 

32). Pipe A can fill a tank in 40 minutes. Pipe B whose diameter is twice as that of Pipe A also fills the tank. lf both the pipes are opened together when the tank is 3/4ths empty, when will the tank be full?
A). 7 minutes 
B). 9 minutes 
C). 5 minutes 
D). 6 minutes 

33). A ship 75 kms from the port springs a leak that admits 3 tonnes of water every 10 minutes. 45 tonnes of water will cause the ship to sink. However, the pumps in the ship can throw out 3 tonnes of water every hour. What should be speed of the ship if she were to reach shore safely?
A). 3 hours 
B). 5 hours 
C). 2 hours 
D). 6 hours 

34). Two inlet pipes fill a cistern in 10 minutes and 15 minutes respectively. An outlet pipe empties the cistern in 5 minutes. All three pipes are opened together when the cistern is full. In how many minutes will the cistern be emptied?
A). 30 minutes 
B). 25 minutes 
C). 27 minutes 
D). 18 minutes 

35). A crack at the bottom of a cistern can empty it in 3 hours. A fill tap that fills water at the rate of 10 litres/min is turned on when the cistern is full and now it takes 6 hours for the tank to empty. What is the capacity of the tank?
A). 2400 Ltrs. 
B). 3600 Ltrs. 
C). 1200 Ltrs. 
D). 2000 Ltrs. 

36). A pipe normally takes B hours to fill a tank. However, due to a crack at the bottom it takes 2 more hours. How long will the crack at the bottom of the tank take to empty a full tank when the fill pipe is kept shut?
A). 20 Hrs. 
B). 36 Hrs. 
C). 40 Hrs. 
D). 48 Hrs. 

37). Pipe A can fill a tank in 20 minutes and pipe B can fill the same tank in 30 minutes. If pipe A is opened and 8 minutes later pipe B is also opened, then in how many minutes will the tank be full?
A). 13.4 minutes 
B). 16.8 minutes 
C). 12.9 minutes 
D). 15.2 minutes 

38). Three fill pipes A, B and C fill a tank in 4, 6 and 8 minutes respectively. Pipe A is opened and after a minute, Pipe B is also opened. Another minute later, Pipe C is also opened. When will the tank be full?
A). \( \Large 2\frac{8}{13} \) 
B). \( \Large 1\frac{11}{13} \) 
C). \( \Large 3\frac{2}{13} \) 
D). \( \Large 1\frac{8}{13} \) 

39). Two fill pipes A and B can fill a tank in 12 minutes and 15 minutes respectively. A drain pipe at the bottom when opened in tandem with the two fill pipes will result in the tank getting filled in 12 minutes. How long will the drain pipe take to empty the tank?
A). 12 minutes 
B). 15 minutes 
C). 18 minutes 
D). 20 minutes 

40). Pipe A and Pipe B fill a tank in 16 and 24 minutes respectively. Another pipe at the bottom, Pipe C drain the tank at the rate of 25 liters per minute. If all three of them are opened simultaneously. then the tank will be full 12 minutes. What is the capacity of the tank?
A). 1000 Ltrs. 
B). 2000 Ltrs. 
C). 1200 Ltrs. 
D). 1600 Ltrs. 
