Question

How many tiles each of $30$ cm $\times$ $20$ cm are required to cover the floor of hall of dimension $15$ m by $12$ m?

Answer 1

Since the tiles are in cm${}^2$, we have to convert the dimensions of the hall to cm first. It will be 1500 cm by 1200 cm. Hence the area of the floor is
$1500\times 1200=1800000c{m}^2$.
Area of each tile is $30\times 20=600c{m}^2$. Hence the number of tiles required to cover the floor is:
$\frac{1800000}{600}=3000$.