$A$ 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 radius of a cylinder is half its height and the curved surface area is $616 \, cm^{2}$. Approximately how many litres of milk can it contain?

The base of a prism is a right-angled triangle with $2$ sides $5 \, cm$ and $12 \, cm$. The height of the prism is $10 \, cm$. The total surface area of the prism is......$cm^2$

$A$ solid cone of height $24 \, cm$ and base radius $8 \, cm$ is melted to form a solid cylinder of radius $6 \, cm$ and height $6 \, cm$. In the whole process,what percent of material is wasted (in $\%$)?

$A$ 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 $cm$)

Calculate the number of bricks,each measuring $25 \, cm \times 15 \, cm \times 8 \, cm$,required to construct a wall with dimensions $19 \, m \times 4 \, m \times 5 \, m$,when $10 \%$ of its volume is occupied by mortar.