Question: (The Von Neumann device) Suppose that one of two people is to be randomly chosen, with equal probability, to attend an important meeting. One of them claims that using a coin to make the choice is not fair because the probability that it will land on a head or a tail is not exactly 0.50. How can the coin still be used for making the choice? (Hint: Toss the coin twice, basing your decision on two possible outcomes.) Explain your answer.