The base of a cone is hemispherical. The radius of the cone is $15 \, cm$ and the total height of the solid is $55 \, cm$. Find the volume of this solid (in $cm^3$).

The diameters of the two circular ends of the bucket are $44 \, cm$ and $24 \, cm$. The height of the bucket is $35 \, cm$. The capacity of the bucket is (in $L$): (in $.7$)

The radius and the height of a cylinder are $28 \, cm$ and $54.5 \, cm$ respectively. It is closed at one end by a hemisphere and at the other end by a $21 \, cm$ high cone. Find the total surface area of the combined article. (in $cm^2$)

If the radius of a sphere is doubled,its volume becomes $\ldots \ldots \ldots \ldots$ times the original volume.

$A$ solid toy is in the form of a hemisphere surmounted by a right circular cone. The height of the cone is $4\, cm$ and the diameter of the base is $8\, cm$. Determine the volume of the toy. If a cube circumscribes the toy,then find the difference of the volumes of cube and the toy. Also,find the total surface area of the toy.

How many balls with diameter $0.5\, cm$ can be produced by melting a metallic cylinder with radius $2\, cm$ and height $8\, cm$?