The table summarizes the distribution of color and shape for tiles of equal area.
| Red | Blue | Yellow | Total | |
|---|---|---|---|---|
| Square | 10 | 20 | 25 | 55 |
| Pentagon | 20 | 10 | 15 | 45 |
| Total | 30 | 30 | 40 | 100 |
If one of these tiles is selected at random, what is the probability of selecting a square tile? (Express your answer as a decimal or fraction, not as a percent.)
