An explorer is captured by a group of cannibals. There are two types of cannibals – those who always tell the truth and those who always lie. The cannibals will barbecue the explorer unless she can determine whether a particular cannibal always lies or always tells the truth. She is allowed to ask the cannibal exactly one question.
a) Explain why the question “Are you a liar?” does not work.
b) Which of the following questions does work in determining whether the cannibal she is speaking to is a truth teller or a liar?
a) Both types of cannibals will answer with “no”.
b) If I were to ask you if you always told the truth, would you say that you did?
Is the color of the sky blue?