The Matching Birthday Problem

Posted on:  April 6, 2014

Several years ago, I encountered a probability problem that was quite interesting. After first reading the problem, it seemed very difficult. The problem went something like this: "Ignoring leap years, find the probability that a room containing n people has at least two people with the same birthday (same month and day, not year)." In this post, I will demonstrate how to use the "probability of at least one" to solve the problem.   Read more