2015 · Q79
The radius of a sphere is equal to the radius of the base of a right circular cone, and the volume of the sphere is double the volume of the cone. The ratio of the height of the cone to the radius of its base is
Elementary MathematicsMensuration
- A2:1
- B1:2
- C2:3
- D3:2
Explanation
This equates the sphere and cone volumes. (4/3)πR³ = 2 × (1/3)πr²h with R = r simplifies to 2r = h, so h:r = 2:1. Option (b) 1:2 is the trap from inverting the ratio; the question asks height-to-radius. Hence option (a).