Floor of a room is of dimensions 5m × 4m and it is covered with circular tiles of diameters 50 cm each as shown in figure. Find area of floor that remains uncovered with tiles. (use π = 3.14)

Length of the floor = l = 5 m

Breadth of the floor = b = 4 m

∴ Area of the floor = l × b = 5 × 4 = 20 m²

Now, Diameter of each circular tile = 50 cm

∴ Radius of each circular tile = r = 25 cm = 0.25 m

Area of one circular tile = πr²

= 3.14 × (0.25)²

= 0.19625 m²

Area of such 80 tiles = 80 × 0.19625

= 15.7 m²

Area of the floor that remains uncovered with tiles =

Area of the floor – Area of all 80 circular tiles

= 20 – 15.7 = 4.3 m²

Hence, the required area of floor that remains uncovered with tiles is 4.3 m².