• A list of interesting probability problems

Birthday Problem

  • Deals with the likelihood of two people sharing the same birthday within a group

  • The probability of a shared birthday becomes quite high with a relatively small number of people

  • The question is usually framed like this: How many people need to be in a room for there to be a 50% chance that at least two of them share the same birthday?

  • The counterintuitive answer is only 23 people are needed to reach a probability of approximately 50%

  • This phenomenon arises from the fact that there are numerous potential pairs of people who could share a birthday in a group, and as the group size increases, the probability of a shared birthday increases more rapidly than one might intuitively expect