The curved surface area of a cylindrical well is $264 \, m^2$ and its volume is $924 \, m^3$. What are the diameter and the depth of the well? (in $m$)

If the volume of a sphere is numerically equal to its surface area,then its diameter is ......... $cm$.

The height of a cone is $30 \, cm$. $A$ small cone is cut off at the top by a plane parallel to the base. If its volume is $\frac{1}{27}$ of the volume of the given cone,at what height above the base is the section made? (in $cm$)

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?

$A$ 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 $cm$)

$A$ 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......$cm$