<t>Well, let (i,j) denote the outcome that the car is behind door i and the other person opens door j. So assuming she deliberately chooses a door without the prize, the only possibilities are (1,2), (1,3), (2,3), (3,2)with probabilities 1/6, 1/6, 1/3, 1/3 respectively, assuming she picks 2 or 3 wit...