Psychological/Decision
Monty Hall Problem
Should you switch doors?
Overview
A counterintuitive probability puzzle where switching doors doubles your winning chances.
You choose one of three doors; one hides a car, two hide goats. The host (who knows) opens a goat door and offers you a chance to switch. Most people think it doesn't matter, but switching actually doubles your winning probability from 1/3 to 2/3.