Question

    ‘X’ and ‘Y’ together can

    complete a work in 12 days, while ‘Y’ and ‘Z’ together can complete the work in 10 days. If ‘Y’ takes 10 days to complete the work alone then find the time taken by all three together to complete 50% of work.
    A 3 days Correct Answer Incorrect Answer
    B 2 days Correct Answer Incorrect Answer
    C 9 days Correct Answer Incorrect Answer
    D 5 days Correct Answer Incorrect Answer
    E 6 days Correct Answer Incorrect Answer

    Solution

    Let the total work = 60 units
    Efficiency of (X + Y) = 60/12 = 5 units/day
    Efficiency of (Y + Z) = 60/10 = 6 units/day
    Efficiency of ‘Y’ = 60/10 = 6 units/day
    Efficiency of (X + Y + Z) = (5 + 6 – 6) = 5 units/day
    Required time taken = (0.50 × 60)/5 = 6 days

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