==> decision/monty.hall.p <==
You are a participant on "Let's Make a Deal." Monty Hall shows you
three closed doors.  He tells you that two of the closed doors have a
goat behind them and that one of the doors has a new car behind it.
You pick one door, but before you open it, Monty opens one of the two
remaining doors and shows that it hides a goat.  He then offers you a
chance to switch doors with the remaining closed door.  Is it to your
advantage to do so?