The Birthday Paradox

If there are 30 people in a room, what are the odds that at least 2 of them share the same birthday?

Most people would tell you that the odds are about 1 in 12. But in fact, they're much higher.


I choose numbers randomly.

Each number has possible values.

What are the odds that at least two of them are the same?

Show all calculations


Written in PERL by Jeff Aaron.