Pipes & Cisterns · Question 8 · Medium
Pipes & Cisterns question 8
Pipes P and Q can fill a tank in 12 hours and 18 hours. Both are opened for 4 hours, then P is closed. How much longer will Q take to fill the tank?
- 6 hours
- 8 hours
- 9 hours
- 10 hours
Answer and explanation
Answer: B. 8 hours
Explanation: In 4 hours both fill 4 × (1/12 + 1/18) = 4 × 5/36 = 5/9. Q fills the remaining 4/9 at 1/18 per hour in 8 hours.
Previous: Pipes A and B fill a tank in 20 minutes and 30 minutes respectively, and pipe… · Next: One pipe fills a tank three times as fast as another. Together they fill it in…
Practise pipes & cisterns
Try a fresh set of pipes & cisterns questions with an explanation after every answer, free and without signing up: Pipes & Cisterns practice. Or sit a full placement mock test.
More pipes & cisterns questions
- A leak at the bottom of a full tank empties it in 8 hours. What part of the…
- A pipe can fill a tank in 4 hours. Because of a leak, it takes 5 hours to…
- Pipes A and B fill a tank in 20 minutes and 30 minutes respectively, and pipe…
- One pipe fills a tank three times as fast as another. Together they fill it in…
- An outlet can empty a full tank in 10 hours. If an inlet that lets in 6 litres…
- Pipes A and B can fill a tank in 15 minutes and 20 minutes. Both are opened…
- Pipe A fills a tank in 6 hours and pipe B in 9 hours. They are opened…
- Three taps A, B and C can fill a tank in 10, 12 and 15 hours respectively. All…
- A tank is half full. An inlet can fill the whole tank in 8 minutes and an…
- Two pipes can fill a tank in 20 minutes and 30 minutes respectively. A drain…
More quantitative aptitude practice
Time, Speed & Distance · Problems on Trains · Boats & Streams · Permutation & Combination · Probability · Data Interpretation · Mensuration · Algebra & Equations
LogicWiz Exams home · All practice topics · Placement mock tests · Daily 10 challenge