HACKER Q&A
📣 ryanthedev

The Birthday Problem


What's the probability of two people sharing the exact birthday? (dd-mm-yyyy)


  👤 wallflower Accepted Answer ✓
It is similar to the problem of grocery checkout. If there are n checkout lines, the probability of being in the quickest line is 1/n, assuming that all checkouts have lines.

It is probably 1/(how many possible birthdays in a given year range). To be conservative (90 years): 1/90*365 or 0.003%.


👤 pwg
1) Open browser

2) Navigate to https://duckduckgo.com/

3) Type in "!w birthday problem" (without the quotes)

4) Read the wikipedia page that appears