New NABARD Grade A 2024 Results out!! Register here for a free live workshop on Feb 26, 2025 at 5 PM. Only on Zoom.

    Question

    A cone and a hemisphere have the same base radius and

    the same height. If the total volume of both is 2,160 cm³, find the radius.
    A 8.8 cm Correct Answer Incorrect Answer
    B 10.4 cm Correct Answer Incorrect Answer
    C 12.6 cm Correct Answer Incorrect Answer
    D 14.8 cm Correct Answer Incorrect Answer
    E 20 cm Correct Answer Incorrect Answer

    Solution

    Volume of cone = (1/3)πr²h Volume of hemisphere = (2/3)πr³ Total volume = (1/3)πr²h + (2/3)πr³ = 2160 Since base radius and height are the same, let h = r. (1/3)πr³ + (2/3)πr³ = 2160 (1/3 + 2/3)πr³ = 2160 πr³ = 2160 r³ = 2160 / π = 2160 / 3.14 ≈ 687.58 r ≈ 8.8 cm Correct Option: a) 8.8 cm

    Practice Next