The diameter of the moon is approximately one-fourth of the diameter of the earth. What fraction of the volume of the earth is the volume of the moon?

The inner diameter of a circular well is $3.5\, m$. It is $10\, m$ deep. Find the cost of plastering this curved surface at the rate of $Rs. 40$ per $m^2$.

$A$ 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 $Rs. 20$.

Twenty-seven solid iron spheres,each of radius $r$ and surface area $S$,are melted to form a single sphere with surface area $S'$. Find the ratio of $S$ to $S'$.

The circumference of the base of a cylindrical vessel is $132 \,cm$ and its height is $25 \,cm$. How many litres of water can it hold (in $,l$)? $(1000 \,cm^3 = 1 \,l)$ Assume $\pi = \frac{22}{7}$.

$A$ right circular cylinder just encloses a sphere of radius $r$ (see figure). Find:
$(i)$ Surface area of the sphere,
$(ii)$ Curved surface area of the cylinder,
$(iii)$ Ratio of the areas obtained in $(i)$ and $(ii)$.