The Girl Named Florida
In The Drunkard's Walk, Leonard Mlodinow presents "The Girl Named Florida Problem":
"In a family with two children, what are the chances, if [at least] one of the children is a girl named Florida, that both children are girls?"
I added "at least" to Mlodinow's statement of the problem to avoid a subtle ambiguity.
I wrote about this problem in a previous article from 2011. As you can see in the comments, my explanation was not met with universal acclaim.
This time, I want to take a different approach.
First, to avoid some real-world complications, let's assume that this question takes place in an imaginary city called Statesville where:
Every family has two children.
50% of children are male and 50% are female.
All children are named after U.S. states, and all state names are chosen with equal probability.
Genders and names within each family are chosen independently.
Second, rather than solve it mathematically, I'll demonstrate it computationally:
Either way, I hope you enjoy getting your head around this problem.