📢 Too many exams? Don’t know which one suits you best? Book Your Free Expert 👉 call Now!

    Question

    Pipe A can fill a tank in 12 hours, and Pipe B can fill

    it in 18 hours. Pipe C can empty the full tank in 36 hours. If all three pipes are opened together, in how many hours will the tank be filled?
    A 4 hrs Correct Answer Incorrect Answer
    B 9 hrs Correct Answer Incorrect Answer
    C 5 hrs Correct Answer Incorrect Answer
    D 7 hrs Correct Answer Incorrect Answer

    Solution

    ATQ, Let total work (capacity of tank) = 1 unit A’s rate = 1/12 per hour B’s rate = 1/18 per hour C’s (emptying) rate = −1/36 per hour Net rate = 1/12 + 1/18 − 1/36 LCM of 12, 18, 36 = 36 1/12 = 3/36 1/18 = 2/36 −1/36 = −1/36 Net = (3 + 2 − 1)/36 = 4/36 = 1/9 Time = 1 / (1/9) = 9 hours

    Practice Next
    More Pipes and cisterns Questions

    Relevant for Exams:

    ask-question