Among the inhabitants of Mars were various kinds of creatures. One type was friendly to visitors from Earth and always told the truth. Another was hostile and always lied to Earthlings. But the astronauts couldn't tell the difference between them. 'Are you a truth-teller?" astronaut John Armstrong asked a striped Martian he met on the way to the dig. "He'll say, 'Yes,' " commented a spotted Martian who was nearby. "But he'll be lying." Who was the truth-teller, the striped Martian or the spotted one?
Answer:
The spotted Martian. Truth-teller or not, the striped Martian would answer yes. Why? If he were a truth-teller, obviously he would tell the truth and say yes. If he were a liar, he would lie and say yes. Therefore, since the spotted Martian said that the striped Martian would say yes, he must be the truth-teller, and the striped Martian must be the liar.
No comments:
Post a Comment