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This was recently released as an old Google interview question and sparked some controversy. This MathOverflow page [1] is a good (opinionated) summary. The be
by tel 16y ago
This was recently released as an old Google interview question and sparked some controversy.
This MathOverflow page [1] is a good (opinionated) summary. The best answer's author believes that with finitely many families the ratio actually doesn't work out evenly, but does converge to 50/50 with infinitely many families.
[1] http://mathoverflow.net/questions/17960/google-question-in-a-country-in-which-people-only-want-boys http://mathoverflow.net/questions/17960/google-question-in-a...
- andreyf 16y agoWell, that's pretty obvious. If it involves an infinite sum, but you only have n people, you don't quite get to that infinity-th guy ;)
- tel 16y agoThe answer suggested that even the expected value is never going to be 1/2 but instead something similar to 1/2-1/(4k) for k families which stop having children after the first boy. So, it's a bit more sophisticated than that involving situations where you test the average percentage of an infinite number of islands with k families each.
- klipt 16y agoThat's specifically talking about the expectation of a ratio though. The expectation of the number of girls is always equal to the number of boys, even for finite families. Expectation of a ratio != ratio of expectations.