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

    Question

    The circumference of a circle is equal to the perimeter

    of a rectangle whose length and breadth are in ratio 9:7, respectively. If the area of the rectangle is 7623 cm2 , then find the radius of the circle.
    A 56 cm Correct Answer Incorrect Answer
    B 52.5 cm Correct Answer Incorrect Answer
    C 53.5 cm Correct Answer Incorrect Answer
    D 49 cm Correct Answer Incorrect Answer
    E 50.5 cm Correct Answer Incorrect Answer

    Solution

    Let the length and breadth of the rectangle be 9x cm and 7x cm, respectively
    According to the question,
    9x × 7x = 7623
    => x2 = 7623/63 = 121
    => x = 11
    Therefore, perimeter of the rectangle = 2 × (9x + 7x) = 352 cm
    Let the radius of the circle be ‘r’ cm
    According to the question,
    2πr = 352
    Or, r = 352 × (7/44) = 56 cm

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