Final answer:
Pat is under a duty to tell her friend the correct figure about the car's gas mileage due to the principle of misrepresentation in law.
Step-by-step explanation:
Pat is under a duty to tell her friend the correct figure about the car's gas mileage. This duty arises from the legal principle of misrepresentation. When Pat intentionally provided false information about the car's gas mileage to her friends, she engaged in misrepresentation.
Under the law, misrepresentation occurs when one party makes a false statement of fact with the intention to deceive, and the other party relies on that false statement to their detriment. In this case, if Pat's friend bought the car based on the false claim Pat made, she could potentially take legal action against Pat for misrepresentation.