Two gentlemen, Sam and Adam, approach you. Sam introduces himself and says, “I am a lawyer, but Adam is an accountant.”
Based on what you know from your previous dealings, what are each of the men’s actual professions?
Both Sam and Adam are lawyers.
Since an accountant ALWAYS tells the truth about everything, he would never say that he is a lawyer. Therefore, Sam must be a lawyer. Since he is telling the truth about being a lawyer, and you know that he always lies about something, he must be lying about the second part of his statement. Therefore, Adam is not an accountant but also a lawyer.