Question

The base radii of a cone and a cylinder are equal. If their curved surface areas are also equal, then the ratio of the slant height of the cone to the height of the cylinder is

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

Answer 1

The correct option is A $2:1$

Let the radius of the cone and cylinder be $r$.

The base radii of cone and cylinder are equal.
Given curved surface areas are equal,
$\therefore \left(\pi \right)rl=2\left(\pi \right)rh$
$\therefore \frac{l}{h}=2$
Hence, option A is correct.