Re:The question is wrong
by jfarmer on Saturday January 03, 2009 @06:54PM
(#418781)
If the FIRST round is black, only two of the four possibilities are left, one of which leads to red.
Similarly, if Atwood's problem stated that the FIRST child is a girl then the probability that the second is a boy is 1/2.
The problem, however, states that one of the children is a girl -- it could be the first or the second. In this case the probability that the other child is a boy is 2/3.
Similarly, if Atwood's problem stated that the FIRST child is a girl then the probability that the second is a boy is 1/2.
The problem, however, states that one of the children is a girl -- it could be the first or the second. In this case the probability that the other child is a boy is 2/3.