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

    Question

    P alone can finish a piece of work ‘M’ in 6 days

    while Q takes 4 days to finish it alone. P, Q and R working together can finish the work ‘N’ which is 10 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
    E 6 days Correct Answer Incorrect Answer

    Solution

     Let the work ‘M’ = 12 units (LCM of 6 and 4) Efficiency of P = 12/6 = 2 units Efficiency of Q = 12/4 = 3 units Efficiency of P, Q and R = (12 × 10)/8 = 15 units per day Efficiency of R = 15 – (2 + 3) = 10 units per day Time taken by R to finish work ‘N’ = 120/10 = 12 days

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