$A$ cylindrical jar of diameter $24\, cm$ contains water to a height of $30\, cm$. $A$ spherical steel ball is dropped into the jar and the level of the water rises by $67.5\, mm$. The diameter of the ball is......$cm$.

If a sphere of radius $r$ is divided into $4$ identical parts,then the total surface area of the $4$ parts is

If a right circular cone of height $24\, cm$ has a volume of $1232\, cm^{3},$ then the area (in $cm^{2}$) of its curved surface is:

$A$ right circular cone is exactly fitted inside a cube in such a way that the edges of the base of the cone are touching the edges of one of the faces of the cube and the vertex is on the opposite face of the cube. If the volume of the cube is $343 \, c.c.$,then what approximately is the volume of the cone? (in $c.c.$)

Find out the amount of concrete required to erect a concrete pillar whose circular base has a perimeter of $8.8\, m$ and whose curved surface area is $17.6\, m^2$. $\left(\pi=\frac{22}{7}\right)$

$A$ right-angled triangle having base $6.3 \, m$ and height $10 \, cm$ is rotated around its height. Find the volume of the cone thus formed. Also,find the curved surface area (in $m^2$). (in $.83$)