If two solid hemispheres of same base radius $r$ are joined together along their bases, then the curved surface area of this new solid is (in $\pi r^{2}$)

$A$ cylinder is closed at both ends by $40 \, cm$ high cones. The radius of the cylinder is $30 \, cm$ and the total height of the article is $180 \, cm$. Find the total surface area of the article. $(\pi = 3.14)$ (in $cm^2$)

$A$ heap of rice is in the form of a cone of diameter $9 \, m$ and height $3.5 \, m$. Find the volume of the rice. How much canvas cloth is required to just cover the heap?

$A$ cylinder with radius $14 \, cm$ is closed at one end by a $48 \, cm$ high cone and at the other end by a hemisphere. If the height of the cylinder is $22 \, cm$,find the total surface area of the article (in $cm^2$).

$A$ metallic spherical shell of internal and external diameters $4 \, cm$ and $8 \, cm$,respectively,is melted and recast into the form of a cone of base diameter $8 \, cm$. The height of the cone is (in $cm$):

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