1 . 
Pipes A and B can fill a tank in 5 and 6 hours, respectively. Pipe C can empty it in 12 hours. The tank is half full. All the three pipes are in operation simultaneously. After how much time, the tank will be full ? 

Answer & Explanation
Answer : Option
D


Explanation : 







2 . 
A cistern has two taps (which fill it in 12 min and 15 min, respectively) and an exhaust tap. When all three taps are opened together, it takes 20 min to fill the empty cistern. How long will the exhaust tap take to empty it ? 

Answer & Explanation
Answer : Option
D


Explanation : 







3 . 
A cistern is filled up in 5 hours and it takes 6 hours when there is a leak in its bottom. If the cistern is full, in what time shall the leak empty it ? 

Answer & Explanation
Answer : Option
C


Explanation : 







4 . 
Pipe A and B running together can fill a cistern in 6 minutes. If B takes 5 minutes more than A to fill the cistern then the times in which A and B will fill the cistern separately will be, respectively: 

Answer & Explanation
Answer : Option
C


Explanation : 







5 . 
Two pipes can fill a tank in 10 hours and 12 hours respectively, while the third can empty it in 20 hours . If all the pipes are opened together, the tank will be filled in : 

Answer & Explanation
Answer : Option
A


Explanation : 







6 . 
A pipe can fill a cistern in 6 hours. Due to a leak in its bottom, it is filled in 7 hours. When the cistern is full, in how much time will it be emptied by the leak? 

Answer & Explanation
Answer : Option
A


Explanation : 







7 . 
Three pipes A, B and C can fill a tank in 6 minuets, 8 minutes and 12 minutes, respectively. The pipe C is closed 6 minutes before the tank is filled. In what time will the tank be full ? 

Answer & Explanation
Answer : Option
A


Explanation : 







8 . 
There are two taps to fill a tank while a third to empty it. When the third tap is closed, they can fill the tank in 10 minutes and 12 minutes, respectively. If all the three taps be opened, the tank is filled in 15 minutes. If the first two taps are closed, in what time can the third tap empty the tank when it is full? 

Answer & Explanation
Answer : Option
A


Explanation : 







9 . 
A cistern has two taps which fill it in 24 minutes and 30 minutes respectively. There is also a waste pipe in the cistern. When all the pipes are opened, the empty cistern is full in 40 minutes. How long will the waste pipe take to empty a full cistern? 

Answer & Explanation
Answer : Option
E


Explanation : 







10 . 
Two taps can fill a tank in 20 minutes and 30 minutes respectively. There is an outlet tap at exactly half level of that rectangular tank which can pump out 50 litres of water per minute. If the outlet tap is open, then it takes 24 minutes to fill an empty tank. What is the volume of the tank? 

Answer & Explanation
Answer : Option
A


Explanation : 







11 . 
Two taps can separately fill a cistern in 10 minutes and 15 minutes, respectively and when the waste pipe is open, they can together fill it in 18 minutes. The waste pipe can empty the full cistern in : 

Answer & Explanation
Answer : Option
C


Explanation : 







12 . 
Two pipes P and Q would fill a cistern in 24 and 32 minutes, respectively. Both pipes are kept open. When should the first pipe be turned off so that the cistern may be just filled in 16 minutes? 

Answer & Explanation
Answer : Option
B


Explanation : 







13 . 
One tap can fill a cistern in 2 hours and another can empty the cistern in 3 hours. How long will they take to fill the cistern if both the taps are open? 

Answer & Explanation
Answer : Option
B


Explanation : 







14 . 
A cistern has a leak which would empty it in 8 hours. A tap is turned on which admits 6 litres a minute into the cistern and it is now emptied in 12 hours. The cistern can hold 

Answer & Explanation
Answer : Option
C


Explanation : 







15 . 
A tap can fill a cistern in 8 hours and another tap can empty it in 16 hours. If both the taps are opened simultaneously, the time taken (in hours) to fill the cistern will be : 

Answer & Explanation
Answer : Option
C


Explanation : 







16 . 
A tap can fill a tank in 16 minutes and another can empty it in 8 minutes. If the tank is already 1/2 full and both the taps are opened together, will the tank be filled or emptied? How long will it take before the tank is either filled or emptied completely as the case may be ? 

Answer & Explanation
Answer : Option
C


Explanation : 







17 . 
A pipe can fill a tank in 15 minutes and another one in 10 minutes. A third pipe can empty the tank in 5 minutes. The first two pipes are kept open for 4 minutes in the beginning and then the third pipe is also opened. In what time will the tank be emptied ? 

Answer & Explanation
Answer : Option
C


Explanation : 







18 . 
Two taps can fill a tank in 60 and 48 min, respectively. A third tap can empty it in 80 min. If all the taps are opened at the same time, then in how much time will the tank be filled ? 

Answer & Explanation
Answer : Option
B


Explanation : 







19 . 
A bath tub can be filled by a cold water pipe in 20 minutes and by a hot water pipe in 30 minutes. A person leaves the bathroom after turning on both pipes simultaneously and returns at the moment when the bath tub should be full. Finding however, that the waste pipe has been open, he now closes it. In 3 minutes more the bath tub is full. In what time would the waste pipe empty it? 

Answer & Explanation
Answer : Option
D


Explanation : 







20 . 
Three pipes A, B and C can fill a tank in 20 min, 10 min and 30 min respectively. When the tank is empty, all the three pipes are opened. A, B, C discharge chemical solutions 'x', 'y', 'z' respectively. The proportion of solution 'y' in the liquid in the tank after 3 min is 

Answer & Explanation
Answer : Option
A


Explanation : 







21 . 
Three taps A, B and C can fill a tank in 12, 15 and 20 h respectively. If A is open all the time and B and C are open for one hour each alternately, the tank will be filled in 

Answer & Explanation
Answer : Option
B


Explanation : 







22 . 
A pump can be operated both for filling a tank and for emptying it. The capacity of tank is 2400 $m^3$. The emptying capacity of the pump is 10 $m^3$ per min higher than its filling capacity. Consequently, the pump needs 8 min less to empty the tank than to fill it. Find the filling capacity of the pump. 

Answer & Explanation
Answer : Option
C


Explanation : 







23 . 
Two pipes A and B can fill a cistern in 12 min and 15 min respectively, while a third pipe C can empty it in 6 min. Both A and B pipes are opened together for 5 min and then the third pipe C is opened. In what time will the cistern be emptied? 

Answer & Explanation
Answer : Option
C


Explanation : 







24 . 
A tank is fitted with 8 pipes, some of them that fill the tank and other pipes are meant to empty the tank. Each pipe that fills the tank can fill it in 8 h, while each of those that empty the tank can empty it in 6 h. All the pipes are kept open. When tank is full, it will take exactly 6 h for the tank to empty. How many pipes are filling the tank? 

Answer & Explanation
Answer : Option
D


Explanation : 







25 . 
A leak in the bottom of a tank can empty the full tank in 6 h. An inlet pipe fills water at the rate of 4 L per min. When the tank is full, the inlet is opened and due to the leak the tank is emptied in 8 h. The capacity of the tank is 

Answer & Explanation
Answer : Option
B


Explanation : 







26 . 
An electric pump can fill a tank in 3 hours. Because of a leak in the tank, it took 3$1 \over 2$ hours to fill the tank. The leak can drain out all the water of tank in 

Answer & Explanation
Answer : Option
C


Explanation : 







27 . 
In what time would a cistern be filled by three pipes running together, whose diameters are 1 cm, 1$1 \over 3$ cm, 2cm, when the largest alone will fill it in 3660 seconds: the amount of water flowing in by each pipe being proportional to the square of its diameter? 

Answer & Explanation
Answer : Option
B


Explanation : 







28 . 
A leak in the bottom of a tank can empty the full tank in 8 hours. An inlet pipe fills water in the tank at the rate of 4 litres per minute. When the tank is full, the inlet is opened and due to a leak, the tank is emptied in 12 hours. How many litres does the cistern hold? 

Answer & Explanation
Answer : Option
B


Explanation : 







29 . 
A cistern has three pipes, A, B and C. The pipes A and B can fill it in 4 and 5 hours respectively and pipe C can empty it in 2 hours. If the pipes are opened in an order at 1, 2 and 3 A.M., when will the cistern be empty? 

Answer & Explanation
Answer : Option
D


Explanation : 







