Jeff Atwood,

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?

This question might have several answers depending upon what the purpose of asking the question was.

If the question was to show that Bayesian Reasoning is very difficult and many people get it wrong {as the link would imply}. Then the answer is 2/3.

If the question was to show that normal people don’t think like CS majors or Mathematicians. Then the answer is near 100%, depending upon the number of percentage of people in a random sample that would happen to be Mathematicians. I wonder what percentage of the populace are Mathematicians.

If the question is posed to make us ask, Are we really given enough information. I should get more detailed information before drawing a conclusion. Then the answer is I don’t know, need more info.

If the question was posed just to hit 1000+ comments, well done.

Please Jeff, stop the madness. What was the point?

Here’s a little joke for you all…

An astrophysicist, a physicist, and a mathematician were on a train riding through Ireland. They looked out the window and saw a black sheep grazing on the pasture.

The astrophysicist says, All of the sheep in Ireland are black.

The physicist chimes in, Your wrong, you only know that there exists in Ireland at least one black sheep.

Your both wrong, the mathematician says, You only know what there exists in Ireland at least one sheep that black on one side.