Answer:
245 tiles
Explanation:
1 meter = 100 cm
Area of bathroom = 3.5m x 2.8m = 350x280 = 9800 cm²
Area of each tile = 20cm x 20cm = 400 cm²
Total number of tiles required = 9800/400 = 245
Note
Strictly speaking we have to find out how many tiles can be fitted in the length and breadth of the bathroom. Since the bathroom is 350 cm wide, we can fit 350/20cm = 17.5 tiles. However, there is no concept of 1/2 tile so the question has an ambiguity. along the width, we can fit 280/10 = 14 tiles
17.5 x 14 = 245 but if the question is reworded to how many tiles do we need to purchase to floor the bathroom it would be 18 x 14 = 252