Question
Pipe ‘A’ takes 30 minutes to fill a tank. Pipe ‘B’ takes 40 minutes to empty the same tank. If pipe ‘B’ is opened 20 minutes after pipe ‘A’, then find the total time taken to fill the tank in this manner.
Solution
Let the capacity of the tank be ‘120’ litres {LCM (30, 40)} Efficiency of pipe ‘A’ = (120/30) = 4 litres/minute Efficiency of pipe ‘B’ = (120/40) = 3 litres/minute Quantity of water filled by pipe ‘A’ in 20 minutes = 4 × 20 = 80 litres Quantity of water to be filled = 120 – 80 = 40 litres Time taken by pipe ‘A’ and ‘B’ together to fill 40 litres of water = {40/(4 – 3)} = 40 minutes Total time taken = 20 + 40 = 60 minutes
More Pipes and cisterns Questions
- Pipe A and Pipe B together can fill the tank in 15 hours. The capacity of the pipe A is 30% of the capacity of the pipe B. How much time will pipe B alone ...
- A tank is filled by two pipes A and B in 12 minutes and 15 minutes, respectively. Another pipe C can empty the tank in 10 minutes. If all three pipes are o...
- Two inlet pipes P and Q are used to fill a tank. Pipe P fills 25 liters in 5 hours and pipe Q fills 60 liters in 5 hours. Pipe P is kept open for 2 hours a...
- Pipes 'A', 'B', and 'C' working together can fill a tank in 4 hours, while pipes 'B' and 'C' together can fill the same tank in 20/3 hours. How long would ...
- Vikas and Vishal can do a job in 7 days and 14 days respectively. They began the work together but 4 days before the completion of job, Vikas leaves the wo...
- Three pipes are attached to a tank. Pipe A can fill it in 20 minutes, pipe B can fill it in 30 minutes, while pipe C can empty the completely filled tank i...
- Pipe ‘A’ can fill a tank in 45 hours. Pipe ‘B’ can empty the same tank in 90 hours. If both are opened simultaneously, how long will it take to fill 60% of...
- Three pipes A, B, and C can fill a tank in 24 minutes, 36 minutes, and 48 minutes respectively. All are opened together. A is closed after 'n' minutes, and...
- Pipe ‘A’ and pipe ‘B’ can fill a cistern in 30 minutes and 10 minutes respectively. Pipe ‘C’ alone can empty the cistern in 12 minutes. If all three pipes ...
- Three pipe P1, P2 and P3 fill the tank in 15 hours, 10 hours and 20 hours respectively. If all the three pipes opened together and pipe P2 & P1 are closed ...
Relevant for Exams:
