[daivd]

The wiki article is not valid, since it considers a subtly different problem than the one I do. If you read the comment at the top of the code, you will see that I changed the question to be less ambiguous.

In the problem I pose, the person does not randomly come forward and tell me "I have a boy born on a tuesday". In my problem I ask random people who I know have two children if they have "at least on boy born on a tuesday" until someone says yes.

[x0054]

My python is really rusty, but if you convert this sudocode to python, you will see that the answer is 50/50. I'll write this up in Javascript when I have time. If you do this in Python, please post.

   girl = 0
   boy  = 0

   do 10000 times {
      child1Sex = randomSex;
      child1Day = randomDay;
      child2Sex = randomSex;
      child2Day = randomDay;
      if ( (child1Sex == "B" AND child1Day == "Tu") OR (child2Sex == "B" AND child2Day == "Tu") ) {
         if (child1Sex == child2Sex){
            boy++
         } else {
            girl++
         }
      }
   }

   print "Ratio of boys and girls is " + boy " : " + girl;

[daivd]

I whipped together something here, before I saw that someone else did it too: http://ideone.com/jyPOhs

It is the most counter-intuitive statistic problem I know (worse than Monty Hall), it trips everyone up at first.

No problem about the stubborness ;)

[krapp]

Here's my attempt in python: http://pastebin.com/tSDK1uRv

the range(0,10000) may not be correct, it might need to be 1,10000

[x0054]

Wow, works good. I should learn python :) But yeah, you were absolutely right! It was hard for me to figure out because I was trying to find a mathematical reason for this, and I was wrong. I finally figured it out mathematically. The way you posit the problem the probability that the asked parents have another boy is (1/2)-(1/7/2).

This is really counter intuitive, the open vs. closed probability set through me off. Hey, thanks for putting up with my stubbornness!