ЁЯУв Too many exams? DonтАЩt know which one suits you best? Book Your Free Expert ЁЯСЙ call Now!

    Question

    Two inlet pipes M and N alone can fill a tank in 10

    hours and 12 hours respectively and an outlet pipe P alone can empty the whole tank in 8 hours. First pipe M is opened for 5 hours, then pipe P is opened for 2 hours and rest of the tank is filled by pipe N. In what time will the tank be filled completely?
    A 21 hrs Correct Answer Incorrect Answer
    B 16 hrs Correct Answer Incorrect Answer
    C 19 hrs Correct Answer Incorrect Answer
    D 22 hrs Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    Total capacity = 120 units (LCM of 10, 12 and 8) Efficiency of pipe M = 120/10 = 12 units/hr Efficiency of pipe N = 120/12 = 10 units/hr Efficiency of pipe P = 120/-8 = -15 units/hr Capacity of tank filled by pipe M in 5 hours = 12 ├Ч 5 = 60 units Capacity of tank emptied by pipe P in 2 hours = -15 ├Ч 2 = -30 units Capacity of tank left for pipe N = 120 тАУ 60 тАУ (-30) = 90 units Time taken by pipe N to fill the remaining tank = 90/10 = 9 hrs Total time taken = 5 + 2 + 9 = 16 hrs

    Practice Next
    More Pipes and cisterns Questions

    Relevant for Exams:

    ask-question