MontyHall: you're given the choice of three doors;
Behind one door is a car; behind the others, goats. You pick a door,
say No. 1, and the host, who knows what's behind the doors, opens
another door, say No. 3, which has a goat. He then says to you,
"Do you want to pick door No. 2?" Is it to your advantage to switch
your choice to win the car?

In this example after a few choices the operator then can chose
one of three options for a 1000 goes. Always keep the initial door
chosen, always swap or swap randomly.

Before the students start get them to suggest the best strategy
keep-swap and why? After running the program what are their
conclusions now? What are their explanations of these results.