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

    Question

    Person 'X' can complete a task in 30 days when working

    at full efficiency, while person 'Y' can finish the same task in 50 days at full efficiency. If 'Y' works at only 62.5% efficiency and 'X' works at only 75% efficiency, how many days will it take for both 'X' and 'Y' to complete the task together?
    A 80/3 days Correct Answer Incorrect Answer
    B 77/3 days Correct Answer Incorrect Answer
    C 67/9 days Correct Answer Incorrect Answer
    D 55/2 days Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    ATQ,

    Time taken by 'X' to do the task with 100% efficiency = 30 days Time taken by 'X' to do the Task with 75% efficiency = 30 × (4/3) = 40 days Time taken by 'Y' to do the task with 100% efficiency = 50 days Time taken by 'Y' to do the task with 62.5% efficiency = 50 × (8/5) = 80 days Task done by both in one day = (1/40) + (1/80) = (3/80) Total time taken to complete the task = (80/3) days

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