Question

Curved surface area of a cone is 60 square centimetres. What is the curved surface area of another cone with same radius but slant height is one third of this cone ?

• A. 45 square centimetres
• B. 60 square centimetres
• C. 30 square centimetres
• D. 20 square centimetres

Hint:

The CSA of a cone is directly proportional to its slant height (CSA l) when the radius is constant. If the slant height becomes (1)/(3) of the original, the CSA will also become (1)/(3) of the original area. So, simply calculate (1)/(3) × 60 = 20.

Answer 1

The Correct Option is D