not what it seems

05122008, 09:22 AM
Post: #1




not what it seems
mrs wilkins has two children call them child a and child b you are told one of them is a girl what are the chances that the other one is a girl? What Are Your Views On Forum Moderation? 

05122008, 12:22 PM
Post: #2




not what it seems
yur recking me hed
bam bam 

05122008, 12:38 PM
Post: #3




not what it seems
Isn't it just 50/50?
"You can put lipstick on a pig...but it's still a pig!!!" 

05122008, 12:40 PM
Post: #4




not what it seems
isn't everything?
bam bam 

05122008, 02:09 PM
Post: #5




not what it seems
survivorfan Wrote:call them child a and child b Not very imaginative are they? I have no idea with this one. You're not born lazy, it's an acquired skill 

05122008, 03:37 PM
Post: #6




not what it seems
it's not 50/50
What Are Your Views On Forum Moderation? 

07122008, 10:13 AM
Post: #7




not what it seems
it's 1 in 3
the possibilities are a = boy b = boy a = boy b = girl a = girl b = girl a = girl b = boy and the first option is out What Are Your Views On Forum Moderation? 

07122008, 02:27 PM
Post: #8




not what it seems
But aren't the second and fourth exactly the same?
Because it wasn't designated in the original question that child a is the girl, or whether it is child b. You're not born lazy, it's an acquired skill 

07122008, 03:45 PM
Post: #9




not what it seems
I think if the original question said child a was a girl then it would be 50/50 that child b was also a girl
What Are Your Views On Forum Moderation? 

07122008, 04:19 PM
Post: #10




not what it seems
Probability depends on the way you define the sample space. It is easy to obtain different answers if you change the sample space. A well known example is the probability of drawing a random chord in a circle such that its length is greater than the side of the inscribed equilateral triangle. The probability can be 1/4, 1/3 or 1/2 depending on how you define a 'random' chord. None of these answers is more 'correct' than the others; they are all correct if the randomness is defined in a particular way.
Now going to your problem with the two children. If the sample space is the total ways that you could have two children then BB, BG, GB, GG is correct and if you cancel BB then probability of one boy, one girl is 2/3. However, if you take the sample space as having one child, then B or G are the two possibilities, and the probability of a boy is 1/2. So if you ask the question BEFORE the second birth the probability of a boy is 1/2. If you ask the question AFTER both children are born then the probability is 2/3. In other words, probability is not a fixed property of some event, it is a function RELATIVE to a framework of events. ^^I don't understand any of that :thumbsup: [SIZE=3] [url="http://www.TickerFactory.com/"] [/url] [/SIZE] 

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