Q. When two pipes work together, then a tank can be filled in 12 hours. One pipe fills the tank comparatively 10 hours faster than the other pipe. How much time will the pipe which is faster take to fill the tank?
A) 20 hrs.
B) 26 hrs.
C) 22 hrs.
D) 30 hrs.
✔ Correct Answer: 20 hrs.
Exam Insight
Let the time taken by the slower pipe be x hours. Then, the faster pipe's time is (x - 10). Their combined rate is 1/12. Solving 1/x + 1/(x - 10) = 1/12 gives x = 20. The faster pipe takes 10 hours.