Switch doors to get a 67% chance of winning the prize. The door you pick 1st has a 67% chance of NOT containing the prize, forcing the host to open the other non-prize door, leaving the door the host didn't open with a 67% chance of hiding the prize.
Palmer

## Switch doors to get a 67%

Switch doors to get a 67% chance of winning the prize. The door you pick 1st has a 67% chance of NOT containing the prize, forcing the host to open the other non-prize door, leaving the door the host didn't open with a 67% chance of hiding the prize.

Palmer