I've got the same questions as Psy-Kosh and DavidAgain. Why?
"Renormalizing leaves us with a 1/3 probability of two boys, and a 2/3 probability of one boy one girl."
help me with this one, i'm n00b.
If one of the kids is known to be a boy (given information), then doesn't the other one has 50/50 chances to be either a boy or a girl? And then having 50/50 chances for the couple of kids to be either a pair of boys or one boy one girl?