2010 · Q66
A solid cylinder of height 9 m has its curved surface area equal to one-third of the total surface area. What is the radius of the base?
Elementary MathematicsMensuration
- A9 m
- B18 m
- C27 m
- D30 m
Explanation
2πrh=(1/3)2πr(h+r) with h=9 gives r=18 m.