11). Three taps A, B and C together can fill an empty cistern in 10 min. The tap A alone can fill it in 30 min and the tap B alone can fill it in 40 min. How long will the tap C alone take to fill it?
A). 16 min 
B). 24 min 
C). 32 min 
D). 40 min 

12). Two pipes P and Q can fill a cistern in 12 and 15 min, respectively. If both are opened together and at the end of 3 min, the first is closed. How much longer will the cistern take to fill?
A). \( \Large 8\frac{1}{4} \) 
B). \( \Large 8\frac{3}{4} \) 
C). 5 min 
D). \( \Large 8\frac{1}{2} \) 

13). There are three pipes connected with a tank. The first pipe can fill \( \Large \frac{1}{2} \) part of the tank in 1 h, second pipe can fill \( \Large \frac{1}{3} \) part of the tank in 1 h. Third pipe is connected to empty the tank. After opening all the three pipes, \( \Large 7\frac{1}{2} \) part of the tank can be filled in 1 h, then how long will third pipe take to empty the full tank?
A). 3 h 
B). 4 h 
C). 5 h 
D). 6 h 

14). A pipe can fill a cistern in 12 min and another pipe can fill it in 15 min, but a third pipe can empty it in 6 min. The first two pipes are kept open for 5 min in the beginning and then the third pipe is also opened. Time taken to empty the cistern is
A). 38 min 
B). 22 min 
C). 42 min 
D). 45 min 

15). A cistern has three pipes A, B and C. Pipes A and B can fill it in 3 and 4 h, respectively, while pipe C can empty the completely filled cistern in 1 h. If the pipes are opened in order at 3:00 pm, 4:00 pm and 5:00 pm, respectively, at what time will the cistern be empty?
A). 6:15 pm 
B). 7:12 pm 
C). 8:12 pm 
D). 8:35 pm 

16). Three pipes A, B and C can fill a tank in 30 min, 20 min and 10 min, respectively. When the tank is empty, all the three pipes are opened. If A, B and C discharge chemical solutions P, Q and R respectively, then the part of solution R in the liquid in the tank after 3 min is
A). \( \Large \frac{8}{11} \) 
B). \( \Large \frac{5}{11} \) 
C). \( \Large \frac{6}{11} \) 
D). \( \Large \frac{7}{11} \) 

17). A tap can fill a tank in 30 minutes and another tap can fill the same tank in 60 minutes. lf both the taps are opened simultaneously when the tank is half empty, in how many minutes will the tank be full?
A). 10 minutes 
B). 18 minutes 
C). 20 minutes 
D). 15 minutes 

18). Pipe A can fill a tank in 40 minutes. Pipe B can fill the same tank in 20 minutes. A crack at the bottom of the tank can empty the tank in 120 minutes. If both the pipes are opened simultaneously when the tank is empty and water gets drained through the crack at the bottom, when will the tank be full?
A). 18 minutes 
B). 15 minutes 
C). 12 minutes 
D). 21 minutes 

19). A pipe can fill \( \Large \frac{2}{3} \)rds of a tank in 16 minutes. How long will it take to fill 3/4ths of the tank?
A). 12 minutes 
B). 15 minutes 
C). 18 minutes 
D). 24 minutes 

20). Pipe A can fill a tank at the rate of 35 gallons in 10 minutes. Pipe A will fill a tank that is \( \Large \frac{x}{3} \)rds empty in 12 minutes. What is the capacity of the tank?
A). 45 gallons 
B). 52 gallons 
C). 60 gallons 
D). 63 gallons 
