Question: A king finds a woman he wants to marry but she refuses. But since he is the king, she has to. The king gives her a deal: he will write 'YES' and 'NO' on two pieces of paper. The papers will be put into a hat and she will choose one. If it says yes she will marry him, if it says no she will not. The only problem is that the king cheats and puts two pieces of paper that say yes into the hat, but the woman is the only one who sees this.
How can the woman avoid marrying the king?
Answer: First she has to draw one of the papers and get rid of it (by eating it, throwing it, etc.). Then they will check the hat and she that the other paper says 'YES', so they know that she drew the paper that said 'NO'. In this case, she doesn't have to marry the king.