$A$ metal sphere with a radius of $12\, cm$ is melted,and recast into cones with radius $3\, cm$ and height $4\, cm$. Find how many cones are obtained?

$A$ well,$20 \, m$ deep,is $7 \, m$ in radius. Find the cost of cementing the inner curved surface at the rate of ₹ $15$ per $m^2$. (in ₹)

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 $m^3$.

$A$ cuboidal water tank is $2\, m$ long,$1\, m$ wide,and $80\, cm$ deep (height). Its remaining five surfaces,excluding the base,are covered with square tiles of size $20\, cm \times 20\, cm$. Find the number of tiles required.

It is required to make a closed cylindrical tank of height $1 \,m$ and base diameter $140 \,cm$ from a metal sheet. How many square metres of the sheet are required for the same (in $,m^2$)? Assume $\pi = \frac{22}{7}$.

$A$ cubical box has each edge $10\, cm$ and another cuboidal box is $12.5\, cm$ long,$10\, cm$ wide and $8\, cm$ high. Which box has the greater lateral surface area and by how much (in $, cm^2$)?