Question

    The circumference of a circle is equal to the perimeter of a rectangle whose length and breadth are in ratio 5:3, respectively. If the area of the rectangle is 1815 cm2 , then find the radius of the circle.

    A 28 cm Correct Answer Incorrect Answer
    B 23 cm Correct Answer Incorrect Answer
    C 22 cm Correct Answer Incorrect Answer
    D 20 cm Correct Answer Incorrect Answer
    E 25 cm Correct Answer Incorrect Answer

    Solution

    Let the length and breadth of the rectangle be 5x cm and 3x cm, respectively
    According to the question,
    5x × 3x = 1815
    => x 2= 1815/15 = 121
    => x = 11
    Therefore, perimeter of the rectangle = 2 × (5x + 3x) = 176 cm
    Let the radius of the circle be ‘r’ cm
    According to the question,
    2πr = 176
    Or, r = 176 × (7/44) = 28 cm

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