A girl meets a lion and unicorn in the forest. The lion lies every Monday, Tuesday and Wednesday and the other days he speaks the truth. The unicorn lies on Thursdays, Fridays and Saturdays, and the other days of the week he speaks the truth. “Yesterday I was lying,” the lion told the girl. “So was I,” said the unicorn. What day is it?
This one could also fall in the lying/truth category. A man is caught on the king’s property. He is brought before the king to be punished. The king says, “You must give me a statement. If it is true, you will be killed by lions. If it is false, you will be killed by trampling of wild buffalo. If I can’t figure it out, I’ll have to let you go.” Sure enough, the man was released. What was the man’s statement?
There are three people (Alex, Ben and Cody), one of whom is a knight, one a knave, and one a spy. The knight always tells the truth, the knave always lies, and the spy can either lie or tell the truth. Alex says: “Cody is a knave.” Ben says: “Alex is a knight.” Cody says: “I am the spy.” Who is the knight, who the knave, and who the spy?
You’re at a fork in the road in which one direction leads to the City of Lies (where everyone always lies) and the other to the City of Truth (where everyone always tells the truth). There’s a person at the fork who lives in one of the cities, but you’re not sure which one. What question could you ask the person to find out which road leads to the City of Truth?