Out of the 50 people in the contingency table, the number of males is 20+7+3 = 30 and the number of full-time employees is 20. However, we cannot simply add these numbers together to get the number of people who are either male or full-time employees because there are some people who are both male and full-time employees, and we don't want to count them twice.
To correct for this, we need to subtract the number of people who are both male and full-time employees (which is 20) from the total number of people who are male or full-time employees (which is 30+20 = 50). Therefore, the number of people who are either male or full-time employees (or both) is 50-20 = 30.
The probability that the person is either male or a full-time employee is therefore:
P(male or full-time employee) = number of people who are either male or full-time employees / total number of people
P(male or full-time employee) = 30/50
P(male or full-time employee) = 0.6
Therefore, the probability that the person is either male or a full-time employee is 0.6, or 60%.