First off, the article I’m referring to is:
I disagree with Jordan Drachman’s second scenario.
You only know that one of the two children is a girl. Case 1 and case 3 are therefore identical.
Your only possible outcomes are:
We know that the second outcome is impossible, therefore there is a 1 in 2 chance that the other child is a boy,
and a 1 in 2 chance that the other child is a girl.
You’re making a common mistake Dan. You mention three cases above, but your three cases do not have equal probability!
There are four possible outcomes:
oldest child = girl, youngest child = boy
oldest child = boy, youngest child = girl
oldest child = boy, youngest child = boy
oldest child = girl, youngest child = girl
So in your case, the male-female combination has probability = 1/2. The other choices have probability 1/4.
Pssst, Arnold, you think this thread should have a better title than “On”?
bugg, you used quotes in the title block, didn’t you?
I’m sure you’re right, Irishman, but the title as it is now has a zen-like simplicity that intrigued me. If our friend bugg asks for a less cryptic title I will be glad to oblige.