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

$A$ hollow hemispherical bowl is made of silver with its outer radius $8\, cm$ and inner radius $4\, cm$. The bowl is melted to form a solid right circular cone of radius $8\, cm$. The height of the cone formed is......$cm$

$A$ cubical metallic tank whose each edge measures $30\, cm$ is completely filled with water. If $2.7\, litres$ of water is taken out of it, what will be the depth of the remaining water in the tank? (in $cm$)

$A$ right cylindrical vessel is full with water. How many right cones having the same diameter and height as those of the right cylinder will be needed to store that water?

$A$ 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.....$cm$

If the heights of two cones are in the ratio $1:5$ and their diameters are in the ratio $5:6$,what is the ratio of their volumes?