New RBI Grade B 2025 Notification will come Soon! Enroll Here

    Question

    20 boys working 9 hours a day can

    finish a task in 12 days. They all worked together initially, but after 10 days, 5 boys left. How long will it take for the remaining boys to finish the leftover work?
    A 24 hrs Correct Answer Incorrect Answer
    B 18 hrs Correct Answer Incorrect Answer
    C 12 hrs Correct Answer Incorrect Answer
    D 10 hrs Correct Answer Incorrect Answer

    Solution

    ATQ, Let the efficiency of each boy be 'b' units/hour Therefore, total work = 20b X 9 X 12 = '2160b' units Amount of work completed in first 10 days = 20b X 9 X 10 = '1800b' units Remaining task = 2160b - 1800b = '360b' units Since, 5 boys left the task, therefore Time taken by 15 men to complete the remaining work = (360b/15b) = 24 hours

    Practice Next

    Relevant for Exams: