Question

    A gardener uses cylindrical roller of diameter 7 cm and

    length 28 cm to flatten a rectangular field of dimension 280cm × 165 cm. Find the number of revolutions made by the roller to flatten the entire field?
    A 225 Correct Answer Incorrect Answer
    B 125 Correct Answer Incorrect Answer
    C 75 Correct Answer Incorrect Answer
    D 150 Correct Answer Incorrect Answer
    E 95 Correct Answer Incorrect Answer

    Solution

    Let number of revolutions be n. => n × 2π (7/2) × 28 = 280 × 165 => n = 280 × 165 × 1/28 × 1/22 => n = 75

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