The number of tiles whose length and breadth are $9 \mathrm{cm}$ and $4 \mathrm{cm}$ respectively that will cover a rectangular region $243 \mathrm{cm}\times 124 \mathrm{cm}$ is tiles.

If the area of a square is given in $\left({\mathrm{cm}}^2\right)$, then what will be the unit of its side?

If perimeter of a field is $2 \mathrm{km}$, how many metres $\left(\mathrm{m}\right)$ of barbed wire is required to fence it?