Curved surface area of a cone = ....................

The curved surface area of a cone with radius $12 \, cm$ and slant height $20 \, cm$ is ....... $\pi \, cm^2$.

The ratio of the radii of two spheres is $3:4$. Then,the ratio of their volumes is $\ldots \ldots \ldots$

The volume of a cylinder is given by:

The radii and heights of a cylinder and a cone are equal. Then,the volume of the cylinder $= \ldots \ldots \ldots \times$ the volume of the cone.

The slant height of a cone with a hemispherical base is $5 \, cm$. If the total surface area of the article is $103.62 \, cm^2$,find its total height. $(\pi = 3.14)$ (in $cm$)