Find the total surface area of a cone,if its slant height is $21 \, m$ and diameter of its base is $24 \, m$. (Take $\pi = \frac{22}{7}$) (in $, m^2$)

Find the volume of the right circular cone with radius $3.5 \, cm$,height $12 \, cm$. Assume $\pi = \frac{22}{7}$. (in $, cm^3$)

$A$ 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 $, cm$)?

Find the capacity in litres of a conical vessel with height $12 \,cm$ and slant height $13 \,cm$.

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 $, cm^2$)

$A$ plastic box $1.5\, m$ long,$1.25\, m$ wide,and $65\, cm$ deep is to be made. It is opened at the top. Ignoring the thickness of the plastic sheet,determine:
$(i)$ The area of the sheet required for making the box.
$(ii)$ The cost of the sheet for it,if a sheet measuring $1\, m^2$ costs $Rs. 20$.