Question

The heights of two cylinders are equal and their radii are in the ratio of 3: 2 then the ratio of their curved surface areas is______

• A. 3: 2
• B. 2: 1
• C. 3: 1
• D. 4: 3

Answer 1

The correct option is A 3: 2

Curved Surface Area of a Cylinder of Radius "r" and height "h" $=2\pi rh$
Let $r_1$ and $h$ be the radius and height of the first cone and $r_2$ and $h$ be the radius and height of the second cone.
Now, ratio of their surface area is calculated as:
$S_1:S_2$
$=2\pi r_{1}h:2\pi r_{2}h$
$=r_1:r_2$
$=3:2$
Hence, their surface areas are in the ratio $3:2$