Uploaded April 2019 | Updated September 2026, 2 weeks ago

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WARNING: If you haven't see this paradox before (and probability isn't your thing), it may seem like math is broken here. I just want to say that it's not and it took me A LOT of thinking to finally see why. I encourage you to watch the video and see what conclusions you come to, but then check out the follow up video (youtu.be/ElB350w8iJo), or pinned comment, for more of an explanation about what's going on.

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What is the chance that a parent has two daughters, given the fact that they have two children, at least one of which is a girl named Julie?

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See pinned comment for additional information.

►References (note, even some of the sources don't fully agree)

en.wikipedia.org/wiki/Boy_or_Girl_paradox
leightonvw.com/2017/03/03/the-puzzling-problem-of-a-girl-named-florida
math.stackexchange.com/questions/2149812/the-two-daughter-problem
math.stackexchange.com/questions/4400/boy-born-on-a-tuesday-is-it-just-a-language-trick
science.slashdot.org/story/10/06/28/2221252/the-tuesday-birthday-problem
allendowney.blogspot.com/2011/11/girl-named-florida-solutions.html

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