How many bricks,each measuring $250\, cm$ by $12.5\, cm$ by $7.5\, cm$,will be required to build a $5\, m$ long,$3\, m$ high and $20\, cm$ thick wall?

If the height of a cone is doubled,then its volume is increased by (in $\%$)

The length of the diagonal of a cube is $6 \text{ cm}$. The volume of the cube (in $\text{cm}^3$) is (in $\sqrt{3}$)

$3$ cubes of metal whose edges are in the ratio $3: 4: 5$ are melted into a single cube,the length of whose diagonal is $48 \sqrt{3} \text{ m}$. Calculate the edges of the three cubes.

$A$ conical vessel of base radius $2 \ cm$ and height $3 \ cm$ is filled with kerosene. This liquid leaks through a hole in the bottom and collects in a cylindrical jar of radius $2 \ cm$. The kerosene level in the jar is.....$cm$

The ratio of the curved surface area and volume of a cylinder is $1:7$. The ratio of the total surface area and volume is $187:770$. What is the ratio of its base radius to its height?