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    Question

    The total surface area of a cube is given as 216 cm².

    The radius of a cone is twice the length of the edge of the cube, and the height of the cone is 16 cm. Calculate the curved surface area of the cone. (take π = 3)
    A 960 sq cm Correct Answer Incorrect Answer
    B 840 sq cm Correct Answer Incorrect Answer
    C 600 sq cm Correct Answer Incorrect Answer
    D 696 sq cm Correct Answer Incorrect Answer
    E 720 sq cm Correct Answer Incorrect Answer

    Solution

    Let the edge of the cube be 'a' cm. Then, total surface area of the cube = 6a2 So, 6a2 = 216 a = 6 Therefore, radius of the cone = 6 X 2 = 12 cm So, slant height of the cone = √(radius) 2 + (height) 2 = √(162 + 122) = √400 = 20 cm So, curved surface area of the cone = π X radius X slant height = 3 X 12 X 20 = 720 cm2

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