Saturday, April 25, 2009

Random

from Randomness Rules our Lives

If a woman has two children and one is a girl, what are the chances that the other child is also female? 50-50, right? But it’s not. The possibilities are girl-girl, girl-boy and boy-girl. So the chance that both children are girls is 33 percent. Once we are told that one child is female, this extra information constrains the odds.

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