Birthday Problem

🎯 Calculate probabilities

You’re attending a party with N guests. Calculate how likely it is that at least two of them will have a birthday on the same day.

Hints

• there are at least two people at the party

• assume that birthdays occur on all days of the year with the same probability.

• ignore leap years

Questions

• How many people have to be there for a >50% or >90% chance?

• What is the probability that there are two or more pairs?

• consider when the assumption that all days have the same probability makes sense

Translated with www.DeepL.com