Length and breadth of the floor of a room are 5 m and 3 m, respectively. Forty tiles, each with area \(\tfrac{1}{16}\,\text{m}^2\), are used to cover the floor partially. Find the ratio of the tiled and the non tiled portion of the floor.
1 : 5
Total floor area = 5 × 3 = 15 m². Tiled area = 40 × (1/16) = 2.5 m². Non-tiled = 15 − 2.5 = 12.5 m². Ratio = 2.5 : 12.5 = 1 : 5.