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

    Question

    A cylindrical road roller has a diameter of 2.2 metres and

    a length of 1.75 metres. If it moves with 14 revolutions per minute, how much area does it roll over in 12 minutes?
    A 2,032.8 m² Correct Answer Incorrect Answer
    B 2,057.9 m² Correct Answer Incorrect Answer
    C 3,350.1 m² Correct Answer Incorrect Answer
    D 4,227.5 m² Correct Answer Incorrect Answer

    Solution

    ATQ,

    CSA = 2 × π × radius × height

    = 2 × (22/7) × (2.2/2) × 1.75

    = 2 × (22/7) × 1.1 × 1.75 = (84.7/7) m²

    Area in 1 minute = 14 × (84.7/7) = 1,185.8/7 m²

    Area in 12 minutes = 12 × (1,185.8/7) = 14,229.6/7 = 2,032.8 m²

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