Question

Find the number of tiles of dimensions $1m\times 0.8m$ required to cover a floor of dimensions $80m\times 120m$.

Answer 1

Hint: As the given floor and tiles are rectangular in shape and we have been given the dimensions of the floor and tiles, so first we calculate the area of one tile and total area of floor by using the formula $\text{Area of rectangle=length}\times \text{width}$. Then, divide the total area of the floor by area of one tile to get the number of tiles required.

Complete step-by-step answer:
We have been given dimensions of a floor $80m\times 120m$ and dimensions of a tile $1m\times 0.8m$.

We have to find the number of tiles required to cover a floor.
Let the length of the floor is $120m$ and width of the floor is $80m$.
As the floor is rectangular in shape, we calculate the area of the floor first.
Area of the floor will be equal to $\text{Area of rectangle=length}\times \text{width}$.
Area of the floor $=120\times 80$
Area of the floor $=9600{{m}^{2}}$
Now, similarly we calculate the area of a tile of dimensions $1m\times 0.8m$.
Let the length of the tile is $1m$ and width of the tile is $0.8m$.
As the tile is rectangular in shape so the area of the floor will be equal to $\text{Area of rectangle=length}\times \text{width}$.
Area of the tile $=1\times 0.8$
Area of the tile $=0.8{{m}^{2}}$
Now, the number of tiles required to cover a floor will be \[\dfrac{\text{Area of floor}}{\text{Area of one tile}}\]
$\begin{align}
  & \Rightarrow \dfrac{9600}{0.8} \\
 & =12000 \\
\end{align}$
So, the number of tiles required to cover a floor is $12000$.

Note: The key concept to solve this question is to calculate the area first. Also, note that we have to check the units of the given dimensions. The units of all the dimensions given must be the same, if not then first we have to convert the units. If the units are not the same then we will get incorrect answer.