The ratio of the curved surface area and the total surface area of a cylinder is $2: 5$. Find the ratio of the radius and height of the cylinder.

$A$ cubical box has each edge $10\, cm$ and another cuboidal box is $12.5\, cm$ long, $10\, cm$ wide and $8\, cm$ high. Which box has the smaller total surface area and by how much (in $ cm^2$)?

The thickness of a metallic tube is $5 \, mm$ and the inner diameter of the tube is $10 \, cm$. Find the mass of a $70 \, cm$ long tube,if the density of the metal is $8 \, g/cm^3$. (in $g$)

The curved surface area of a cone is $550 \, cm^2$. If the radius of the cone is $7 \, cm$,find its volume in $cm^3$.

The diameter of a solid hemisphere is $7 \, cm$. Find its curved surface area and total surface area (in $cm^2$).

The radius of a sphere is $6\, cm$. It is melted and drawn into a wire of diameter $1\, cm$. Find the length of the wire (in $m$).