41). Pipe A will fill a tank in 24 minutes and Pipe B will fill the same tank in 36 minutes. There is a drain pipe at the bottom which will empty the tank in 30 minutes. lf the drain pipe is opened 8 minutes after pipe A and pipe B are opened, when will the tank be full?
A). 18.6 minutes 
B). 15.9 minutes 
C). 17.5 minutes 
D). 20.3 minutes 

42). Two pipes A and B fill a tank. Pipe A fills the tank thrice as fast as Pipe B. lf both pipes are kept open together when the tank is empty, the tank will be full in 18 minutes. How long will pipe B alone take to fill the tank?
A). 72 minutes 
B). 64 minutes 
C). 58 minutes 
D). 50 minutes 

43). A pump can be used either to fill or to empty a tank. The capacity of the tank is 3600 \( \Large m^{2} \). The emptying capacity of the pump is 10 \( \Large \frac{m^{2}}{min} \) higher than its filling capacity. What is the emptying capacity of the pump if the pump needs 12 more minutes to fill the tank than it takes to empty the tank?
A). \( \Large 40 m^{3}/min \) 
B). \( \Large 60 m^{3}/min \) 
C). \( \Large 80 m^{3}/min \) 
D). \( \Large 100 m^{3}/min \) 

44). Pipe A can fill the tank in 30 minutes and pipe B can fill the same tank in 20 minutes. Both the pipes are kept open simultaneously. When should pipe B be switched off, so that the tank may fill in exactly 24 minutes?
A). 5 minutes 
B). 7 minutes 
C). 4 minutes 
D). 3 minutes 

45). Two pipes A and B can fill a tank in 45 minutes and 40 minutes respectively. They are kept open simultaneously and after some time pipe A was switched off. Pipe B fills the rest of the tank in 23 minutes after pipe A was switched off. How long was pipe A kept open?
A). 5 minutes 
B). 8 minutes 
C). 6 minutes 
D). 9 minutes 

46). If a pipe fills a tank in 6 h, then what part of the tank will the pipe fill in 1 h?
A). \( \Large \frac{1}{3} \) 
B). \( \Large \frac{1}{6} \) 
C). \( \Large \frac{1}{4} \) 
D). \( \Large \frac{1}{5} \) 

47). An outlet pipe can empty a cistern in 30 min, then what part of the cistern will it empty in 1 min?
A). \( \Large \frac{1}{20} \) 
B). \( \Large \frac{1}{15} \) 
C). \( \Large \frac{1}{30} \) 
D). \( \Large \frac{1}{18} \) 

48). An inlet pipe fills \( \Large \Large \frac{1}{8} \) part of a tank in 1 h. How much time will the pipe take to fill the empty tank?
A). 4h 
B). 2h 
C). 6h 
D). 8h 

49). An outlet pipe can empty a cistern in 3 h. In what time will the pipe empty twothird part of the cistern?
A). 4h 
B). 2h 
C). 3h 
D). 5h 

50). Three pipes A, B and C can fill a tank separately in 8 h, 10 h and 20h, respectively. Find the time taken by all the three pipes to fill the tank when the pipes are opened together.
A). \( \Large 5\frac{7}{11} \) 
B). \( \Large 4\frac{7}{11} \) 
C). \( \Large 8\frac{7}{11} \) 
D). \( \Large 3\frac{7}{11} \) 
