That's not how it goes. And, yes, the answer is 50% in this case. The problem relies on first choosing a door (1). The host then opens a door that you did NO

That's not how it goes. And, yes, the answer is 50% in this case. The problem relies on first choosing a door (1). The host then opens a door that you did NOT choose (3) and asks if you want to switch your choice to door #2. In this case, the probability that the goat is behind door 2 is not 50%. https://en.wikipedia.org/wiki/Monty_Hall_problem https://en.wikipedia.org/wiki/Monty_Hall_problem