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 No Subject by Matt)

Matt you claim: "Never once does it say it must be the birthday of somebody in the line." But the puzzle says: "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 also claim that "By looking at it, to where it doesnt have to be the same month as someone elses in line, ..." (What did you think the birthday would match?) "... the 1st person is guaranteed it." Since there are no previous purchasers, there is nothing for person number 1 to match. He is guaranteed not to win.

Edited on March 30, 2004, 5:44 am

Posted by TomM on 2004-03-30 05:38:20