UPSC CDS Math Volume and Surface Area Questions

Let the radius and height of the cone and cylinder be r and h, respectively.Suppose the number of cones obtained be n.Therefore, 30 × Volume of each cylinder = n × Volume of each cone$\Rightarrow n = \frac{30 \times \pi r^2 h}{\frac{1}{3} \pi r^2 h} = 90$Hence, statement I is correct.The curved surface of the cylinder can be flattened in the shape of a rectangle but the curved surface of the cone when flattened has the shape of a sector.Hence, statement II is not correct.