The Problem of the Unfinished Game

Today’s post is a simple question.

Let’s say, hypothetically speaking, you met someone who told you they had two children, and one of them is a girl. What are the odds that person has a boy and a girl?

Consider your answer carefully, without doing a web search, or reading the comments to this post. Don’t cheat – but be prepared to explain your reasoning, because the solution might surprise you.

It’s almost like some kind of conspiracy or something.

Jeff Atwood

Written by Jeff Atwood

Indoor enthusiast. Co-founder of Stack Overflow, Discourse, and RGMII. Disclaimer: I have no idea what I'm talking about. Let's be kind to each other. Find me https://infosec.exchange/@codinghorror

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