Competitive Exams : Quantitative Aptitude - Pipes and Cistern (Set 5) | Concept of Maths

Question 1

Two inlet pipes A and B can fill a cistern in 12 hours and 15 hours respectively. If both are opened together, how long will they take to fill the empty cistern?

Accepted Answer

A) 6 hours 40 minutes

Answer

B) 7 hours

Answer

C) 5 hours 30 minutes

Answer

D) 8 hours

Question 2

A pipe can fill a tank in 16 hours. Due to a leak in the bottom, it takes 24 hours to fill the tank. If the tank is full, how long will the leak take to empty it?

Accepted Answer

C) 48 hours

Answer

A) 32 hours

Answer

B) 40 hours

Answer

D) 36 hours

Question 3

Three pipes P, Q, and R can fill a reservoir in 6 hours. After working together for 2 hours, R is closed and P and Q can fill it in 8 additional hours. How many hours would R alone take to fill the reservoir?

Accepted Answer

B) 12 hours

Answer

A) 10 hours

Answer

C) 15 hours

Answer

D) 18 hours

Question 4

Pipe A can fill a tank in 10 hours and Pipe B can empty it in 15 hours. If both are opened simultaneously in an empty tank, how long will they take to fill it completely?

Accepted Answer

B) 30 hours

Answer

A) 25 hours

Answer

C) 20 hours

Answer

D) 35 hours

Question 5

A cistern is filled by three pipes A, B, and C in 5 hours. Pipe C is twice as fast as B, and B is twice as fast as A. How much time will pipe A alone take to fill the cistern?

Accepted Answer

C) 35 hours

Answer

A) 25 hours

Answer

B) 30 hours

Answer

D) 40 hours

Question 6

Two pipes can fill a tank in 20 and 24 minutes respectively, and a waste pipe can empty 3 gallons per minute. All three pipes working together can fill the tank in 15 minutes. What is the capacity of the tank?

Accepted Answer

B) 120 gallons

Answer

A) 60 gallons

Answer

C) 100 gallons

Answer

D) 150 gallons

Question 7

A tank has a leak which can empty it in 8 hours. An inlet pipe fills water at the rate of 6 liters a minute. When the tank is full, the inlet is opened and due to the leak, the tank is emptied in 12 hours. What is the capacity of the tank in liters?

Accepted Answer

B) 8640 liters

Answer

A) 7200 liters

Answer

C) 9000 liters

Answer

D) 5760 liters

Question 8

Two pipes A and B can fill a cistern in 15 hours and 20 hours respectively. Both pipes are opened together, but after 4 hours, pipe A is turned off. What is the total time required to fill the cistern?

Accepted Answer

B) 14 hours 40 minutes

Answer

A) 12 hours 20 minutes

Answer

C) 15 hours

Answer

D) 13 hours 10 minutes

Question 9

Pipe A can fill a tank in 6 hours and Pipe B can fill it in 8 hours. Both pipes are opened together. After how much time should Pipe B be closed so that the tank is completely filled in 4 hours?

Accepted Answer

A) 2 hours 40 minutes

Answer

B) 3 hours

Answer

C) 2 hours

Answer

D) 1 hour 45 minutes

Question 10

A large container can be filled by an inlet pipe in 12 minutes and emptied by an outlet pipe in 15 minutes. If they are opened on alternate minutes starting with the inlet pipe, how long will it take to fill the container?

Accepted Answer

B) 111 minutes

Answer

A) 115 minutes

Answer

C) 120 minutes

Answer

D) 109 minutes

Question 11

Three pipes A, B, and C can fill a tank in 10, 15, and 30 hours respectively. If Pipe A is open all the time and B and C are open for one hour each alternately, in how many hours will the tank be full?

Accepted Answer

B) 6 hours 36 minutes

Answer

A) 6 hours

Answer

C) 7 hours

Answer

D) 5 hours 45 minutes

Question 12

Two pipes A and B can fill a cistern in 36 minutes and 45 minutes respectively. A waste pipe C can empty the cistern in 30 minutes. A and B are opened together. After 7 minutes, C is also opened. In how much total time is the cistern filled?

Accepted Answer

A) 46 minutes

Answer

B) 42 minutes

Answer

C) 40 minutes

Answer

D) 48 minutes

Question 13

A tap can fill a tank in 6 hours. After half the tank is filled, three more similar taps are opened. What is the total time taken to fill the tank completely?

Accepted Answer

A) 3 hours 45 minutes

Answer

B) 4 hours

Answer

C) 3 hours 30 minutes

Answer

D) 4 hours 15 minutes

Question 14

Two pipes A and B can fill a tank in 12 minutes and 15 minutes respectively. If both are opened and after 3 minutes, A is closed, how much longer will it take for B to fill the tank?

Accepted Answer

B) 8 minutes 15 seconds

Answer

A) 7 minutes 30 seconds

Answer

C) 9 minutes

Answer

D) 8 minutes 45 seconds

Question 15

One pipe can fill a tank three times as fast as another pipe. If together the two pipes can fill the tank in 36 minutes, then the slower pipe alone will be able to fill the tank in how many minutes?

Accepted Answer

C) 144 minutes

Answer

A) 81 minutes

Answer

B) 108 minutes

Answer

D) 192 minutes

Question 16

A tank is filled in 5 hours by three pipes A, B and C. The pipe C is twice as fast as B and B is twice as fast as A. How much time will pipe B alone take to fill the tank?

Accepted Answer

B) 17 hours 30 minutes

Answer

A) 15 hours

Answer

C) 20 hours

Answer

D) 22 hours

Question 17

Two pipes A and B can fill a tank in 24 minutes and 32 minutes respectively. If both pipes are opened together, after how much time should B be closed so that the tank is full in 18 minutes?

Accepted Answer

B) 8 minutes

Answer

A) 6 minutes

Answer

C) 10 minutes

Answer

D) 12 minutes

Question 18

A booster pump can fill a pool in 4 hours. But because of a leak, it takes 5 hours to fill it. If the pool is full and the pump is off, how many hours will it take for the leak to empty the pool?

Accepted Answer

B) 20 hours

Answer

A) 15 hours

Answer

C) 25 hours

Answer

D) 30 hours

Question 19

If two pipes function simultaneously, a pool is filled in 12 hours. One pipe fills the pool 10 hours faster than the other. How many hours does the faster pipe take to fill the pool?

Accepted Answer

B) 20 hours

Answer

A) 15 hours

Answer

C) 25 hours

Answer

D) 30 hours

Question 20

A cistern has three pipes A, B, and C. A and B can fill it in 3 hours and 4 hours respectively, while C can empty it in 1 hour. If all three are opened at 1 PM, 2 PM, and 3 PM respectively, at what time will the cistern be completely empty?

Accepted Answer

A) 5:12 PM

Answer

B) 6:00 PM

Answer

C) 4:48 PM

Answer

D) 5:30 PM