2022 · Q73
Consider the following for the next three (03) items that follow: A conical vessel has radius 12 cm and height 16 cm. A sphere is inscribed in the cone. What is the ratio of the lateral surface area of the vessel to the surface area of the sphere?
Elementary MathematicsMensuration
- A4/3
- B3/2
- C5/3
- D2
Explanation
Lateral surface area of the cone = π·12·20 = 240π; sphere surface = 4π·36 = 144π; the ratio is 240/144 = 5/3. Using the total surface area (including the base) instead of the lateral area is the usual trap here. The keyed option is C.