In the Monty Hall Problem, the host (Monty Hall) asks a contestant to choose one of three curtains. Behind one and only one of these curtains is a fabulous prize, such as an all-expense paid vacation, and behind the other two curtains are much less valuable prizes; let’s suppose donkeys. At this point, the contestant has no reason to prefer one curtain over the other two. After the contestant chooses, Monty opens one of the remaining two curtains to reveal a donkey and gives the contestant the opportunity to switch from his original (and still unopened) curtain to the remaining one. What should the contestant do, stay with the original choice or switch to the unopened curtain? Set up a simulation model to determine whether it is better to stay or switch.