Question

A bucket is in the form of a frustum of a cone. The curved surface area of the bucket is $270\pi c{m}^2$. The top and bottom radius of the bucket is $3$cm and $6$cm. What is the slant height?

• A. $10$ cm
• B. $20$ cm
• C. $30$ cm
• D. $40$ cm

Answer 1

The correct option is C $30$ cm

Curved surface area $=\pi (R+r)s$
$270\pi =\pi (6+3)\times s$
$\frac{270}{9}=s$
$s=30$ cm