Odds of a Girl

I read great new book called The Drunkard’s Walk which is essentially about how the random effects our lives more than we imagine. He had a number of interesting examples of how to think in these terms, all pointing to the importance of asking the right questions and thinking about how to answer it right ways.

For instance if you ask, “A family has two children, one of which is a girl. What are the chances the other one is too?” The answer is 1:3. That’s because we know there are the following combinations possible in birth order: (girl, boy), (girl, girl), and (boy, girl). The (boy, boy) combination is ruled out by what was said about the family. So three equal possibilities, odds are 1:3 that the family would be (girl, girl).

Ah but what if one of the children were named Florida? What then of the odds? It turns out to be 1:2. I’ll show you how in my next post.

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