Water flows into a tank with a base of $150\, m \times 100\, m$ through a pipe with a cross-section of $2\, dm \times 1.5\, dm$ at a speed of $15\, km/h$. In what time will the water reach a depth of $3\, m$? (in $hours$)

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 ...... $cm$.

$A$ $4\, cm$ cube is cut into $1\, cm$ cubes. What is the ratio of the total surface area of all the small cubes to the surface area of the large cube?

$A$ rectangular plot,$36 \, m$ long and $28 \, m$ broad,has two concrete roads $5 \, m$ wide running in the middle of the park,one parallel to the length and the other parallel to the breadth. What would be the total cost of gravelling the plot,excluding the area covered by the roads,at ₹ $3.60$ per $m^{2}$? (in $Rs.$)

The radius of the base of a solid cylinder is $r \text{ cm}$ and its height is $3 \text{ cm}$. It is recast into a cone of the same radius. The height of the cone will be (in $\text{cm}$):

The radii of two cones are in the ratio $2:1,$ and their volumes are equal. Find the ratio of their heights.