$A$ cylinder with base radius of $8\, cm$ and height of $2\, cm$ is melted to form a cone of height $6\, cm.$ The radius of the cone will be (in $cm$):

The number of coins,each of radius $0.75\, cm$ and thickness $0.2\, cm$,to be melted to make a right circular cylinder of height $8\, cm$ and radius $3\, cm$ is:

The total number of spherical bullets,each of diameter $5$ decimetre,that can be made by utilizing the maximum of a rectangular block of lead with $11$ $m$ length,$10$ $m$ breadth and $5$ $m$ width is (assume that $\pi > 3$)

$A$ hollow cylinder of height $3\,cm$ is recast into a solid cylinder. If the external and internal radii of the hollow cylinder are $4.3\,cm$ and $1.1\,cm$ respectively,what will be the radius of the solid cylinder? (in $cm$)

The cross section of a canal is in the shape of an isosceles trapezium which is $4 \ m$ wide at the bottom and $5 \ m$ wide at the top. If the depth of the canal is $2 \ m$ and it is $120 \ m$ long,what is the maximum capacity of this canal? (in $m^3$)

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