Question

Surbhi wants to cover the floor of her room whose length is $4m$ and breadth is $3m$ by square tiles. If each square tile is of side $20cm$, then find the number of tiles required to cover the floor of her room.

Answer 1

Step 1: Convert the units of all quantities into centimetres

Length of the room $l=4m=4\times 100=400cm$ $[\therefore 1m=100cm]$

Breadth of the room $b=3m=3\times 100=300cm$

Side of each square tile $a=20cm$

Step 2: Find the area of the floor and each tile

The floor is in the form of a rectangle.

Therefore, the area of the floor of Surbhi's room$=l\times b$

$$\begin{gathered} =400\times 300 \\ =120000c{m}^2 \end{gathered}$$

Also, tiles are in the form of square.

Thus, area of each tile $=a^2$

$$\begin{gathered} ={20}^2 \\ =20\times 20 \\ =400c{m}^2 \end{gathered}$$

Step 3: Find the number of tiles required

$Thenumberoftilesrequired=\frac{Areaofthefloor}{Areaofeachtile}$

$$\begin{gathered} =\frac{120000}{400} \\ =300 \end{gathered}$$

Hence, the number of square tiles required is equal to $300.$