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

    Question

    P alone can finish a piece of work ‘M’ in 8

    days while Q takes 4 days to finish it alone. P, Q and R working together can finish the work ‘N’ which is 15 times of work ‘M’ in 8 days. How long will R take to finish work ‘N’, when working alone?
    A 8 days Correct Answer Incorrect Answer
    B 15 days Correct Answer Incorrect Answer
    C 10 days Correct Answer Incorrect Answer
    D 12 days Correct Answer Incorrect Answer

    Solution

    Let the work ‘M’ = 8 units (LCM of 8 and 4) Efficiency of P = 8/8 = 1 units Efficiency of Q = 8/4 = 2 units Efficiency of P, Q and R = (8 × 15)/8 = 15 units per day Efficiency of R = 15 – (1 + 2) = 12 units per day Time taken by R to finish work ‘N’ = 120/12 = 10 days

    Practice Next

    Relevant for Exams: