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14. You are at a party with a friend and 10 people are present including you and the friend. your friend makes you a wager that for every person you find that h

14. You are at a party with a friend and 10 people are present including you and the friend. your friend makes you a wager that for every person you find that has the same birthday as you, you get $1; for every person he finds that does not have the same birthday as you, he gets $2. would you accept the wager? Is this a trick question? The answer is a definite no right? Or is there some tricky detail that I am missing? If the answer is no what is the question for? To see that the candidate can think clearly and don't try to come up with "smart" solutions when not needed?

tlrobinson 18y ago
At first glance this seemed like it might have something to do with the birthday paradox (http://en.wikipedia.org/wiki/Birthday_paradox http://en.wikipedia.org/wiki/Birthday_paradox) but that only says something about the probability that a pair of people out of a group has the same birthday, not the probability that a single person has the same birthday as someone in the group. Now, if the bet were "I win $x if any two people at the party have the same birthday, you win $x if none do" then that is exactly the birthday paradox. If there are 23 or more people at the party then the probability is greater than 50% and you should take the bet. So unless I'm missing something it's either a stupid question or a trick question.