Awesome Birthday Paradox

[Rt&Dzine]

Just a fun fact I'm sure many of you know, but it's interesting nonetheless. If you go to the main Mac Forums page and scroll all the way down, you can see all the birthdays for that day. It's crazy how many members have the same birthday on any given day.

Have you ever noticed how many of them haven't posted since 2003?

(Also, it doesn't include all members.)

 

[0098386]

Have you ever noticed how many of them haven't posted since 2003?

(Also, it doesn't include all members.)

Oh nice find! Also it seems that you can check any date you want - https://forums.macrumors.com/calendar.php?do=getday&day=2010-03-16&sb=1
Using the year-month-day format.

 

[savar]

By my count it took us only 10 people, not 23, to get a birthday match (March 22, between fireshot91 and pit29). The odds were good that it wouldn't take more than a forum page, and we beat even those odds!

Please don't post more birthdays in this thread. You are welcome to talk about this or other surprising facts of probability and math.

The birthday paradox can be used in cryptology as well:

http://en.wikipedia.org/wiki/Birthday_attack

Also, here's another similar mind bender involving probability:

http://en.wikipedia.org/wiki/Monty_Hall_problem