New Enroll in RBI Gr B 2025 Exclusive New Batch on March 18

    Question

    A frustum of a cone has radii of 8 cm and 5 cm, and the

    slant height is 13 cm. Find the total surface area of the frustum.
    A 546 cm² Correct Answer Incorrect Answer
    B 562.15 cm² Correct Answer Incorrect Answer
    C 585.42 cm² Correct Answer Incorrect Answer
    D 653.12 cm² Correct Answer Incorrect Answer

    Solution

    The surface area of a frustum of a cone is given by: Surface Area = πl(r₁ + r₂) + π(r₁² - r₂²) Where l is the slant height, r₁ and r₂ are the radii of the two ends. Substitute the values: Surface Area = 3.14 × 13 × (8 + 5) + 3.14 × (8² - 5²) Surface Area = 3.14 × 13 × 13 + 3.14 × (64 - 25) Surface Area = 3.14 × 169 + 3.14 × 39 Surface Area = 3.14 × 208 Surface Area = 653.12 cm² Correct Option: d

    Practice Next

    Relevant for Exams: