Problem 3. A pedestrian path with a rectangular shape has a length of $3030 \mathrm{~m}$ and a width of $180 \mathrm{~cm}$. The path needs to be covered with square tiles whose area is $9 \mathrm{~dm}^2$. How many such tiles are needed?
Solution. First method. We will convert all dimensions to decimeters. Thus, the length of the path is equal to $3030 \cdot 10=30300 dm$, the width is $180: 10=18 dm$, and the area of the path is

$$
P=30300 \cdot 18=545400 \mathrm{dm}^{2}
$$

Each tile covers $9 \mathrm{dm}^2$, so it follows that a total of $545400: 9=60600$ tiles are needed.

Second method. The length of the path is $3030 \cdot 10=30300 dm$, the width is $180: 10=18 dm$. (6) From $3 \cdot 3=9 \mathrm{dm}^2$ it follows that the length of the side of the tile is 3dm. Therefore, in one row across the width of the path, we need to place $18: 3=6$ tiles, and along the length of the path, we need to place $30300: 3=10100$ rows of 6 tiles each. According to this, for tiling the path, a total of $10100 \cdot 6=60600$ tiles are needed.