Final answer:
It is illegal for a minor to ask a bartender for a beer for their adult friend.
Step-by-step explanation:
In the United States, the legal drinking age is typically 21. Therefore, it is illegal for a minor to ask a bartender for a beer for their adult friend. The bartender would be breaking the law by selling alcohol to a minor. Additionally, it is important to note that providing false identification or attempting to deceive a bartender is also illegal.