Question

Floor of a room is of dimensions $5m\times 4m$ and it is covered with circular tiles of diameters 50 cm each as shown in fig. Find the area of floor that remains uncovered with tiles. (Use $\pi =3.14$)

Answer 1

As the diameter of circular tile is $50cm$ each, then $radius=\frac{0.5}{2}=0.25m$

Number of tiles lengthwise $=\frac{5}{0.5m}=10tiles$

Number of tiles widthwise $=\frac{4}{0.5m}=8tiles$

So, $10$ tiles are length wise and $8$ tiles are width wise.

So, total number of tiles $=10\times 8=80$

$\therefore$ Area of floor not covered by tiles

Area of rectangular floor - Area of $80$ tiles

$=5\times 4-80\pi r^2=20-80\times \pi \times 0.25\times 0.25$

$=20-\frac{8\times 314\times 25\times 25}{100\times 100\times 100}=20-\frac{157}{10}=20-15.7=4.3m^2$

Hence,the area of floor not covered by tiles $=4.3m^2$