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 $m$).

$A$ school provides milk to the students daily in cylindrical glasses of diameter $7\, cm$. If the glass is filled with milk up to a height of $12\, cm$, find how many litres of milk is needed to serve $1600$ students. (in $0.2$)

In a cylinder,if the radius is doubled and the height is halved,the curved surface area will be:

The dimensions of each iron hollow box are $30 \, cm \times 15 \, cm \times 10 \, cm$. What is the volume of a carton containing $60$ such boxes? (in $m^3$)

$A$ 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 greater lateral surface area and by how much (in $, cm^2$)?

If $V$ is the volume of a cuboid of dimensions $a, b, c$ and $S$ is its total surface area,then prove that $\frac{1}{V} = \frac{2}{S} \left( \frac{1}{a} + \frac{1}{b} + \frac{1}{c} \right)$.