Question

    The diameter of a sphere is twice the diameter of

    another sphere, The surface area of the first sphere is equal to the volume of the second sphere, The magnitude of the radius of the first sphere is
    A 17 Correct Answer Incorrect Answer
    B 24 Correct Answer Incorrect Answer
    C 16 Correct Answer Incorrect Answer
    D 48 Correct Answer Incorrect Answer

    Solution

    let radius of sphere 1 = r1 radius of sphere 2 = r2 Given, r1 = 2 r2 surface area of sphere 1 = volume of sphere 2 4π(r1)2 = 4/3 π(r2)3 r1 = 2 r2 4π(2r2)2 = 4/3 π(r2)3 4 = 1/3(r2) r2 = 12 r1 = 2 r2 = 2 × 12 = 24  

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