$A$ monument has $50$ cylindrical pillars each of diameter $50\, cm$ and height $4\, m.$ What will be the labour charges for cleaning these pillars at the rate of $50$ $paise$ per $m^{2}?$ (in $Rs.$) (Use $\pi=3.14$)

The base of a right prism is an equilateral triangle. If the lateral surface area and volume are $120 \, cm^2$ and $40 \sqrt{3} \, cm^3$,respectively,then the side of the base of the prism is ...... $cm$.

$A$ cylinder,a hemisphere,and a cone stand on the same base and have the same heights. Find the ratio of their volumes and also the ratio of the areas of their curved surfaces.

If a cube with its edge $6 \ cm$ is melted and smaller cubes with edge $2 \ cm$ each are formed,then how many cubes are formed?

$A$ rectangular water tank has dimensions $80\, m \times 40\, m$. Water flows into it through a pipe with an opening area of $40\, cm^{2}$ at a speed of $10\, km/hr$. By how much will the water level rise in the tank in half an hour (in $cm$)?

The diameter of a copper sphere is $18 \, cm$. The sphere is melted and drawn into a long wire of uniform circular cross-section. If the length of the wire is $108 \, m$,the diameter of the wire is ....... $cm$.