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# Probability and Birthdays

_AVG_
Here's a probability question:

"There are two football (soccer) teams on the pitch along with the referee making it 23 people totally. Is it more probable or less probable that two people on the pitch share the same birthday?"

Afaceinthematrix
It's about the same... At 23 people the probability is about 50% (if my memory serves me correct, the percentage is slightly - not very much - higher than 50%... it's been a while since I've calculated it out).
Bikerman
Hmm...same here. I seem to remember the probability at 49% for a coincident birthday vs 51% against....I'd have to do the sums to confirm that and I've got a lot of other stuff to do at the moment
Xanatos
Are we talking about the same birthday as in same day and month, or as in same day?
Bikerman
 Xanatos wrote: Are we talking about the same birthday as in same day and month, or as in same day?

Same day and month.

Here's a link (which saves me having to do the maths again - I once calculated this and it took me a while )
http://mathforum.org/dr.math/faq/faq.birthdayprob.html
Afaceinthematrix
I did a bit of looking and found another great link with the problem. It's a wiki link. I like it because it includes tables and graphs... Likewise, I've done the calculating and I do not want to do it again as it takes a while and it's easier to just use google.