this constraint was unclear to me in the original problem statement, which is why I thought she was wrong, too. It wasn't until somebody wrote in a letter saying they wrote a computer program that I understand what the rules were, and then it was obvious.

I wish the problem was stated more clearly to say, the host has to choose the door with goat.

> I wish the problem was stated more clearly to say, the host has to choose the door with goat.

Yes, that one point would make many people instantly realize the probability changed. Nevertheless, you'd think mathematicians and statisticians sending her offensive letters should've known better.

Right, and the host is only making a meaningful choice in the 2/3 scenarios where you didn't pick the car in the first place.