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

    Question

    P alone can finish a piece of work ‘M’ in 10 days

    while Q takes 6 days to finish it alone. P, Q and R working together can finish the work ‘N’ which is 8 times of work ‘M’ in 10 days. How long will R take to finish work ‘N’, when working alone?
    A 16 days Correct Answer Incorrect Answer
    B 15 days Correct Answer Incorrect Answer
    C 13.5 days Correct Answer Incorrect Answer
    D 12 days Correct Answer Incorrect Answer
    E 14 days Correct Answer Incorrect Answer

    Solution

     Let the work ‘M’ = 30 units (LCM of 10 and 6) Efficiency of P = 30/10 = 3 units Efficiency of Q = 30/6 = 5 units Efficiency of P, Q and R = (30 × 8)/10 = 24 units per day Efficiency of R = 24 – (3 + 5) = 16 units per day Time taken by R to finish work ‘N’ = 240/16 = 15 days

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