📢 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 P can fill a cistern in 12 hours and pipe Q in 20

      hours. If both the pipes are opened in an empty cistern, how much time will they take to fill it?
      A 10 hours Correct Answer Incorrect Answer
      B 7.5 hours Correct Answer Incorrect Answer
      C 8 hours Correct Answer Incorrect Answer
      D 12 hours Correct Answer Incorrect Answer

      Solution

      Let the capacity of tank be 60 litres (LCM of 12 and 20)
      Efficiency of 'P' = (60 / 12) = 5 litres/hour
      Efficiency of 'Q' = (60 / 20) = 3 litres/hour
      Required time = 60 ÷ (5 + 3) = 7.5 hours

      Practice Next

      Relevant for Exams:

      ask-question