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    Question

    A sphere 'A' has a volume of 256 cm³, and its radius is

    'r' cm. If the radius of another sphere 'B' is (r + 1) cm, calculate the curved surface area (in cm²) of sphere 'B'. (Take π = 3)
    A 500 cm² Correct Answer Incorrect Answer
    B 200 cm² Correct Answer Incorrect Answer
    C 300 cm² Correct Answer Incorrect Answer
    D 320 cm² Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    ATQ; (4/3) × 3 × r³ = 256 4r³ = 256 r³ = 64 ⇒ r = 4 cm So, radius of sphere 'B' = (r + 1) = 5 cm Curved Surface Area = 4πr² = 4 × 3 × 5² = 4 × 3 × 25 = 300 cm²

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