F CHARLIE Posted January 13, 2014 Share Posted January 13, 2014 Explain? If we know that one child is a boy. Then to prob of second being boy is 50/50. The answer is in the phrase. In the first example we only need to determine the sex of the younger child. In the second example without knowing which child is which since its a probability question we must use three of four possible outcomes when determining the sex of each. If there are 2 children there are 4 possible outcomes. The only outcome that is invalid is that both are girls. Link to comment Share on other sites More sharing options...
#NewWizard Posted January 13, 2014 Share Posted January 13, 2014 The answer is in the phrase. In the first example we only need to determine the sex of the younger child. In the second example without knowing which child is which since its a probability question we must use three of four possible outcomes when determining the sex of each. If there are 2 children there are 4 possible outcomes. The only outcome that is invalid is that both are girls. I looked the question up on google and http://en.wikipedia.org/wiki/Boy_or_Girl_paradox. 1/2 is the correct answer too. Link to comment Share on other sites More sharing options...
F CHARLIE Posted January 13, 2014 Share Posted January 13, 2014 I looked the question up on google and http://en.wikipedia.org/wiki/Boy_or_Girl_paradox. 1/2 is the correct answer too. Read it again. It depends on how it is phrased. Since you don't know which is what sex you are left with a paradox. Edit. Here are the outcomes: child #? Can be a b or g. Other child #? Can be a b or g Pairing combinations. B and g, b and b, g and g, g and b The only outcome that I'd invalid is b and b. This leaves the combination outcomes with 3. Each of those three is valid according to the sentence. Link to comment Share on other sites More sharing options...
There Posted January 13, 2014 Share Posted January 13, 2014 Let's say that Jones has two kids: child #1 and child #2. Child #2 is older than child #1, and therefore will always be a girl. However, we don't know for child #1, so it could either be a boy or girl. Therefore, the options (1|2) are B|G or G|G. 1/2 Now Smith has two kids: child #1 and child #2. But we don't know which one is a boy. But we do know that he doesn't have two girls. Therefore, we options are (1|2) B|B, B|G, or G|B. 1/3 Link to comment Share on other sites More sharing options...
MC22 Posted January 14, 2014 Share Posted January 14, 2014 conditional probability is fun Link to comment Share on other sites More sharing options...
F CHARLIE Posted January 14, 2014 Share Posted January 14, 2014 Paradox of Toil http://en.wikipedia.org/wiki/Paradox_of_toil Thoughts Link to comment Share on other sites More sharing options...
Grimes Posted January 21, 2014 Share Posted January 21, 2014 Pinocchio paradox: If Pinocchio says "My nose is going to grow now, his nose will grow, as it is a lie. This then means that it wasn't a lie, creating a never ending loop of growing and shrinking. Link to comment Share on other sites More sharing options...
Liddojunior Posted January 21, 2014 Share Posted January 21, 2014 Yes but the holocaust might not have, Its debatable whether Hitler used the holocaust to create a war or the war to create to holocaust. He was going to war either way. The war was about how every country shamed Germany and blamed them for WW 1 when it wasn't their fault. And the holocaust could have been avoided multiple times. Thank the US and other countries for declining to help the victims of the holocaust before the public started supporting the war. Death camps started when he was already losing the war. Stalin is much worse than hitler and the US didnt care that there was a holocaust. It was never a priority to help the victims at the camps, and it was only used to bring in more support for the war. Just so happened that troops went by the camps on their march toward important places/cities. Link to comment Share on other sites More sharing options...
Python. Posted January 22, 2014 Share Posted January 22, 2014 Pinocchio paradox: If Pinocchio says "My nose is going to grow now, his nose will grow, as it is a lie. This then means that it wasn't a lie, creating a never ending loop of growing and shrinking. This has been said before :3 Link to comment Share on other sites More sharing options...
Wombat Posted January 22, 2014 Share Posted January 22, 2014 "This statement is false" Link to comment Share on other sites More sharing options...
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