Question

    Radius of base of a hollow cone is 8 cm and its height

    is 15 cm. A sphere of largest radius is put inside the cone. What is the ratio of radius of base of cone to the radius of sphere?
    A 5 : 3 Correct Answer Incorrect Answer
    B 4 : 1 Correct Answer Incorrect Answer
    C 2 : 1 Correct Answer Incorrect Answer
    D 7 : 3 Correct Answer Incorrect Answer

    Solution

    Let ABC is ∆ We can see that ∆ CPO and ∆ CKB similar ∠ P = 900 tangent angle CO = CK – OK CO = 15 – r 15 – r / 17 = r/8 = 17r = 120 – 80 = 25r = 120 R = 24 / 5 = 4.8 = 8 : 4.8 = 80 : 48 = 10 ; 6 = 5 : 3

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