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

    Question

    A and B can complete a piece of work in 12 days and 15

    days respectively. They start working together, but after 4 days, A leaves. In how many more days will B complete the remaining work?
    A 6 days Correct Answer Incorrect Answer
    B 7 days Correct Answer Incorrect Answer
    C 8 days Correct Answer Incorrect Answer
    D 9 days Correct Answer Incorrect Answer

    Solution

    Work done by A and B in 1 day = (1/12 + 1/15) = 5/60 + 4/60 = 9/60 = 3/20. Work completed by A and B together in 4 days = 4 * (3/20) = 12/20 = 3/5. Remaining work = 1 - 3/5 = 2/5. Work done by B in 1 day = 1/15. Time taken by B to complete 2/5 of the work = (2/5) ÷ (1/15) = (2/5) * 15 = 6 days. Correct Option: a

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