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

    Question

    'R' takes 20 days to complete a task, and 'A' takes 30

    days to do the same task. To finish the job in just 6 days, what percentage increase in their respective efficiencies is required by 'R' and 'A'?
    A 75% Correct Answer Incorrect Answer
    B 25% Correct Answer Incorrect Answer
    C 100% Correct Answer Incorrect Answer
    D 95% Correct Answer Incorrect Answer
    E 55% Correct Answer Incorrect Answer

    Solution

    We can say that Let the total work = 60 units (L.C.M of 20 & 30) Efficiency of 'R' = 60/20 = 3 units /day Efficiency of 'A' = 60/30 = 2 units/day Their combined efficiency = 2 + 3 = 5 units/day To complete the work in 6 days, there combined efficiency should be 60/6 = 10 units/day Required percentage increase = {(10 – 5) × 100}/5 = 100%

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