The volume of a right circular cone is $9856 \, cm^3$. If the diameter of the base is $28 \, cm$,find the curved surface area of the cone. (in $, cm^2$)

In the figure,you see the frame of a lampshade. It is to be covered with a decorative cloth. The frame has a base diameter of $20 \, cm$ and a height of $30 \, cm$. $A$ margin of $2.5 \, cm$ is to be given for folding it over the top and bottom of the frame. Find how much cloth is required for covering the lampshade. $\left[ \text{Assume } \pi = \frac{22}{7} \right]$ (in $, cm^2$)

$A$ capsule of medicine is in the shape of a sphere of diameter $3.5 \, mm$. How much medicine (in $mm^3$) is needed to fill this capsule (in $, mm^3$)?

The capacity of a closed cylindrical vessel of height $1 \, m$ is $15.4$ litres. How many square metres of metal sheet would be needed to make it (in $, m^{2}$)?

$A$ small indoor greenhouse (herbarium) is made entirely of glass panes (including base) held together with tape. It is $30 \, cm$ long,$25 \, cm$ wide,and $25 \, cm$ high. How much tape is needed for all the $12$ edges (in $, cm$)?

The diameter of a metallic ball is $4.2\, cm$. What is the mass of the ball,if the density of the metal is $8.9\, g/cm^3$ (in $, g$)?