Riddle: You are hiking in remote woods when you accidentally stumble upon a primitive tribe. You are captured and tied to a stake. The head tribesman says to you "i will let you choose how you die. Make a statement and if it is true, you will die by arrow. If it is false, you will die by fire" Assuming the tribesman will know the truthfulness of anything you say, what statement can you make that will keep you alive?
Answer: Say "I will die by fire"
If the tribesman says this is true, he would kill you be arrow making it untrue.
If he says it is false, he would kill you by fire and make it true.
He is then forced to let you go.