I was asked the question “a man states he has two children, and at least one of them are boys, what are the odds that the man has two boys?” I’ve been told the answer is 1/3, but I can’t wrap my head around it. Additionally, there is another version of the problem that states he has at least one boy born on a Tuesday. How does that change the odds? Why?
Edited to add (so people don’t have to sort through replies): the answer is 1/3 because “at least one boy” is accounting for B/G & G/B. The girl can be the first or second child. You can move the odds to 50/50 by rewording the question to “my first of two children is a boy, what are the odds the other child is a boy”
In: Mathematics
One fourth of all parents with two children have two girls, one fourth have two boys and a half has a girl and a boy.
So, if you consider 400 pairs, 100 of them have two boys and 300 have one or two boys. 100 is a third of 300.
Maybe sometimes it helps to convert a question about probablility into a question about distributions.
Latest Answers