You sign up for a class at a local college, and you go to your first lecture. You get there first and sit in the middle of the classroom. What are the chances that the person that sits to your right is male? You cannot say 50/50 because of the 2 possible outcomes. If the school has a 90% female population, the chances are only 10%. Suppose the whole school has 4000 students; what are the chances that there is at least one other person in that school that shares your birthday?