Question

A right circular cone and a right circular cylinder have equal base and equal height. If radius of the base and the height, are in the ratio 5:12, then ratio of the total surface area of the cylinder to that of the cone is

• A. 3:1
• B. 13:9
• C. 17:9
• D. 34:9

Answer 1

The correct option is C 17:9

Surface area of cylinder $=2\pi r^2+2\pi rh$
Surface area of cone $=\pi rl+\pi r^2$
Substitute $r=5,h=12$ and $l=13,$ we get required ratio $=\frac{17}{9}$