2023 · Q62
Two times the total surface area of a solid right circular cylinder is three times its curved surface area. If h is the height and r is the radius of the base of the cylinder, then which one of the following is correct?
Elementary MathematicsMensuration
- Ah = r
- Bh = 2r
- C2h = 3r
- D3h = 4r
Explanation
Twice the total surface area equals thrice the curved surface area: 2(2πr² + 2πrh) = 3(2πrh). Simplifying gives 4πr² = 2πrh, i.e. 2r = h (B).