At a movie theater, the manager announces that they will give a free ticket to the first person in line whose birthday is the same as someone who has already bought a ticket. You have the option of getting in line at any time. Assuming that you don't know anyone else's birthday, that birthdays are distributed randomly throughout the year, etc., what position in line gives you the greatest chance of being the first duplicate birthday?

from http://www.ocf.berkeley.edu/~wwu/riddles/hard.shtml

(In reply to re: Function [with observations] by Jer)

Interesting.  Yours and Tristan's formula's do not look like they are equal!  Can you enlighten us on how you got yours?  Also, how do you get the x(x-1)=365 thing (which is the same as (x-1/2)^2=365 1/4)?

Also, welcome to perlexus.  By the way, you get promoted from Novice to Student only by making some ratings -- Students and higher can edit their comments but Novices cannot.

Posted by Richard on 2004-03-31 17:19:55