📢 Too many exams? Don’t know which one suits you best? Book Your Free Expert 👉 call Now!
  • google app store apple app store
    • ✖

      Question

      Pipe X can fill a tank in 25 minutes, pipe Y can fill it

      in 50 minutes, while pipe Z can empty it in 20 minutes. Pipe X is opened first, pipe Y after 5 minutes, and pipe Z after 10 minutes. Find the total time taken to fill the tank.
      A 40 min Correct Answer Incorrect Answer
      B 45 min Correct Answer Incorrect Answer
      C 50 min Correct Answer Incorrect Answer
      D 55 min Correct Answer Incorrect Answer
      E 60 min Correct Answer Incorrect Answer

      Solution

      Let the capacity of the tank be 100 litres. {LCM (25, 50 and 20)}
      So, efficiency of inlet pipe X = 100 ÷ 25 = 4 litres/minute
      And, efficiency of inlet pipe Y = 100 ÷ 50 = 2 litres/minute
      And, efficiency of outlet pipe Z = 100 ÷ 20 = 5 litres/minute
      In first 5 minutes, pipe X will fill 5 × 4 = 20 litres
      And, pipes X and Y together will fill 5 × (4 + 2) = 30 litres
      So, required time = 5 + 5 + {(100 − 20 − 30) ÷ (4 + 2 − 5)} = 60 minutes

      Practice Next
      More Pipes and cisterns Questions

      Relevant for Exams:

      ask-question