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

    Question

    A and B together can complete a task in 12 days. A alone

    can complete the task in 20 days. In how many days can B alone complete the task?
    A 30 days Correct Answer Incorrect Answer
    B 35 days Correct Answer Incorrect Answer
    C 40 days Correct Answer Incorrect Answer
    D 45 days Correct Answer Incorrect Answer

    Solution

    Let the total work be 60 units (LCM of 12 and 20). A's rate of work = 60 / 20 = 3 units/day. A and B together = 60 / 12 = 5 units/day. B's rate of work = 5 − 3 = 2 units/day. Time taken by B = 60 / 2 = 30 days. Thus, the correct answer is 30 days . Ans. a

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