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

    Question

    ‘A’ alone can do some work in 13 days. ‘B’ and

    ‘C’ together can do the same work in 18 days. If ‘B’ is half as efficient as ‘A’, then find the time taken by ‘C’ to complete the work alone.
    A 54.5 days Correct Answer Incorrect Answer
    B 50.5 days Correct Answer Incorrect Answer
    C 58.5 days Correct Answer Incorrect Answer
    D 51.5 days Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    Let the total work be 234 units. {LCM (13 and 18)} So, efficiency of ‘A’ = (234/13) = 18 units/day So, efficiency of ‘B’ = (18 x 0.5) = 9 unit/day Efficiency of ‘B’ and ‘C’ together = (234/18) = 13 units/day So, efficiency of ‘C’ = 13 – 9 = 4 units/day So, time taken by ‘C’ to finish the work alone = (234/4) = 58.5 days

    Practice Next