Originally Posted by CyberSEO

It was not. Because the 3rd door was a fake. Doesn't matter which door you have chosen, your "math teacher" has removed the empty one form the equation at the beginning and you have only two rooms to choose. In fact the 3rd door has never existed at all (it was not a part of the equation). So you initially had a 50/50 chance and it hasn't changed (once again: because one of 3 doors was a virtual fake - a decoration). So where the people get 66, which is actually 67 because 66.6(6) is always rounded to 67, I don't understand. I'm used to look at the real facts and I don't give my attention to distracting elements.