$A$ matchbox measures $4 \,cm \times 2.5 \,cm \times 1.5 \,cm.$ What will be the volume of a packet containing $12$ such boxes (in $,cm^3$)?

The diameter of a solid hemisphere is $21 \, cm$,then its volume is $\ldots \ldots \ldots \, cm^3$.

In the auditorium,there are $20$ cylindrical pillars. Each pillar has a radius of $14 \, cm$ and a height of $5 \, m$. Find the cost of painting the curved surface of all the pillars at the rate of ₹ $120$ per $m^2$.

The paint in a certain container is sufficient to paint an area equal to $9.375 \,m^2$. How many bricks of dimensions $22.5 \,cm \times 10 \,cm \times 7.5 \,cm$ can be painted out of this container?

The circumference of the base of a cylindrical vessel is $440\, cm$ and its height is $80\, cm$. Find the volume of the cylinder in $m^3$.

$30$ circular plates,each of radius $14\,cm$ and thickness $3\,cm$,are placed one above the other to form a cylindrical solid. Find:
$(i)$ the total surface area
$(ii)$ the volume of the cylinder so formed.