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Statistics puzzle: probability of belonging to a group
Posted:
Oct 11, 2007 10:24 AM


I'm struggling with the following puzzle:
I have a group of friends of which 60% is male. I have a group of colleagues of which 70% is male.
Someone I know is both a friend and a colleague.
What is the chance that this person is male?
a) < 60 % b) 60 % c) between 60 en 70% d) 70% e) > 70%
(and why?)
Thanks for your help!  BigFurryMonster



