The ratio of radii of two cylinders is $3:4$ and the ratio of their heights is $4:5$. Then,the ratio of their volumes is ..........

$A$ solid consisting of a right circular cone of height $120\, cm$ and radius $60\, cm$ standing on a hemisphere of radius $60\, cm$ is placed upright in a right circular cylinder full of water such that it touches the bottom. Find the volume of water left in the cylinder,if the radius of the cylinder is $60\, cm$ and its height is $180\, cm$. [Take $\pi = \frac{22}{7}$.] (in $m^3$)

During the conversion of a solid from one shape to another,the volume of the new shape will

How many balls with diameter $1 \, cm$ can be produced by melting a metallic cylinder with radius $6 \, cm$ and height $4 \, cm$?

$A$ metallic sphere of radius $4.2 \, cm$ is melted and recast into the shape of a cylinder of radius $6 \, cm$. Find the height of the cylinder. (in $cm$) [Take $\pi = \frac{22}{7}$]

$A$ metallic cylinder with radius $15\, cm$ and height $20\, cm$ is melted and recast to produce identical balls with radius $3\, cm$. Find the number of balls produced.