2021 · Q73
A tub is in the shape of a frustum of a cone. The radii of two circular ends of the tub are 105 cm and 42 cm. If the vertical height of the tub is 16 cm, what is its slant height ?
Elementary MathematicsMensuration
- A63.5 cm
- B65 cm
- C73.5 cm
- D75 cm
Explanation
For a frustum, slant height l = √(h² + (R−r)²) = √(16² + (105−42)²) = √(256 + 3969) = √4225 = 65 cm. This is option (b).