Refer to the table below that displays the lunch selections of employees at an office cafeteria:
| Salad ordered | Salad not ordered | Total | |
|---|---|---|---|
| Drink purchased | 45 | 55 | 100 |
| Drink not purchased | 30 | 20 | 50 |
| Total | 75 | 75 | 150 |
What is the probability that a randomly selected employee did not purchase a drink?
