Question

The ratio of total surface area to lateral surface area of a cylinder whose radius is 20 cm and height 60 cm is ____.

• A. 2:1
• B. 3:2
• C. 4:3
• D. 5:3

Answer 1

The correct option is C 4:3

Given,
Radius of cylinder is 20 cm.
Height of cylinder is 60 cm.

Now,

$\frac{TotalSurfaceArea}{LateralSurfaceArea}$

$=\frac{2\pi rh+2\pi r^2}{2\pi rh}$

$=\frac{2\pi r(h+r)}{2\pi rh}$

$=\frac{h+r}{h}$

$=\frac{60+20}{60}$

$=\frac{4}{3}$

Hence, the required ratio is 4:3.