How many small cubical blocks of side $5\, cm$ can be cut from a cubical block whose each edge measures $20\, cm$?

The material of a cone is converted into the shape of a cylinder of equal radius. If the height of the cylinder is $5\, cm$,the height of the cone is........$cm$.

$3$ spherical balls of radii $1\, cm$,$2\, cm$,and $3\, cm$ are melted to form a single spherical ball. In the process,the loss of material is $25\%$. The radius of the new ball is.........$cm$.

How many bricks,each measuring $25\, cm \times 11.25\, cm \times 6\, cm$,will be needed to build a wall $8\, m \times 6\, m \times 22.5\, cm$?

Two $cm$ of rain has fallen on a square $Km$ of land. Assuming that $50 \%$ of the raindrops could have been collected and contained in a pool having a $100 \, m \times 10 \, m$ base,by what level would the water level in the pool have increased?

$A$ $1 \, m^3$ of metal weighing $90 \, Kg$ is rolled into a square bar $9 \, m$ long. An exact cube is cut off from the bar. How much does it weigh? (in $kg$)