SSC CPO 2024 PYQ — Question 107

The correct answer is option 3 i.e. 15 $\pi$.

Given that, radius = 3 cm

Height = 4 cm

CSA of cone = $\pi rl$

Also, l² = r² + h²

where l is slant height, r is radius and h is height of cone.

According to the given question,

l² = r² + h²

⇒ l² = 3² + 4²

⇒ l² = 9 + 16

⇒ l² = 25

⇒ l = 5 cm

Now,  CSA of cone = $\pi\times 3 \times 5$

⇒ 15$\pi$

Hence the curved surface area of the cone is 15$\pi$.