Final answer:
The minimum age to legally serve alcohol differs by state, typically ranging from 18 to 21 years old, so it is crucial to check the specific state regulations.
Step-by-step explanation:
The minimum age that an individual can legally serve alcohol varies by state or country due to different liquor laws. In the United States, the federal minimum age for serving alcohol in a restaurant is set at 18, but each state has the authority to establish its own legal age, which can range from 18 to 21 years old. It's important to check the specific state regulations where the restaurant is located to determine the exact minimum age for serving alcohol legally.