Quote Originally Posted by Zenrax View Post
Each of the doors has a 1/3 chance of having the car. Thus, whichever door you pick has a 2/3 chance of being a goat. When the goat door is opened, it doesn't change the probability of your door having a goat. So you have the door you picked, with a 2/3 chance of being a goat, and the door you didn't pick, with a 2/3 chance of being the car. Switching makes the most sense.
I hate this question because the accepted "answer" is wrong. You say:

When the goat door is opened, it doesn't change the probability of your door having a goat
IF that is true then it also doesn't change the probabilty of the the 3rd door being the car. Meaning there is a 1/3 chance of it being the car - the excat same as the door you have chosen.

If you are to re figure the math and say the other door has a 1/2 chance of being the car . so does the one you have chosen.

You can't re figure the odds for one scenario and not the other and say they are even.