When you select the door, you partition the set of doors into two subsets, the door you chose and the doors that you did not choose. At this stage the probabilities of the prize being in the partitions is fixed - 1/3…
When you select the door, you partition the set of doors into two subsets, the door you chose and the doors that you did not choose. At this stage the probabilities of the prize being in the partitions is fixed - 1/3…