Total surface area of a hemisphere with diameter $2 \, cm$ is $\ldots \ldots \ldots cm^{2}$.

The radii of a frustum of a cone are $10\,cm$ and $7\,cm$. If its height is $4\,cm$, then its curved surface area is $\ldots \ldots \ldots \,cm^2$. (in $\pi$)

For a cone,$l = \ldots \ldots \ldots \ldots$

The radii of two $10 \, cm$ high metallic cylinders are $3.5 \, cm$ and $7 \, cm$. These cylinders are melted and recast to produce a cylinder with height $50 \, cm$. Find the radius of this new cylinder (in $cm$).

Volumes of two spheres are in the ratio $64: 27$. The ratio of their surface areas is

The base of a cone with radius $0.6 \ m$ and height $1.6 \ m$ is hemispherical. Find the volume of this combined solid in $m^{3}$.