3 ms·

Is it not 50%?

• hanoz 7y ago
  It is not.
  • deleted 7y ago
    [deleted]
  • deleted 7y ago
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• nwallin 7y ago
  Having once male child eliminates the possibly of having two female children. You take a four entry truth table and scratch one out. The truth table is male->female, female->male, male->male. Tuesday is a red herring. Note that there's some ambiguity between exactly one of vs at least one of which changes the probability but not as much as 1/2->1/3. (exactly one male on a Tuesday excludes the possibility of two males born on a Tuesday) Tuesday is not a red herring. It's truth tables all the way down.
  • AnotherGoodName 7y ago
    Ahh i see. It's because the ordering doesn't matter. If the question made the ordering matter; "I have two children, the youngest is a boy, what is the probability that i have two boys" Then it's definitely 50%. The truth table would be Youngest: Boy Oldest: Girl Youngest: Boy Oldest: Boy Youngest: Girl Oldest: Girl Youngest: Girl Oldest: Boy With the bottom two being ruled out by the question. I think that's the part that catches people out here.