The gameshow Lets Make a Deal had a seemingly simple final round.. There were 3 doors.. Behind 1 door was a car, behind the others were dummy prizes.. A contestant was to pick a door that they thought had the car.. When they did this, the host would open one of the other two doors, which was inevitably a gag-gift door.. At this point the contestant was given the option to trade the door that they chose, for the remaining unopened door.. Which is the smarter decision if there is one, and why?