New Enroll in RBI Grade B New Batch - Starts on May 21

    Question

    E and F can complete a task in 24 days together. E alone

    can do it in 40 days. Find the time F alone would take.
    A 48 days Correct Answer Incorrect Answer
    B 56 days Correct Answer Incorrect Answer
    C 60 days Correct Answer Incorrect Answer
    D 66 days Correct Answer Incorrect Answer

    Solution

    Let the total work be 120 units. {LCM (24 and 40)}
    So, combined efficiency of 'E' and 'F' = 120 ÷ 24 = 5 units/day
    Efficiency of 'E' = 120 ÷ 40 = 3 units/day
    So, efficiency of 'F' = 5 - 3 = 2 units/day
    So, time taken by 'F' to do the work alone = 120 ÷ 2 = 60 days

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