Suppose you've three coins in your pocket: 2 coins are fair and have head upon one side and tail on the other, 1 coin has a head on both sides of the coin. You reach in your pocket, pull out a coin, and place it upon the table. You see a head. What is the chance that it is one of the fair coins? What is the process you used to come up with your answer? How could you adapt this process if you added more coins to your pocket to start with?