27th March 2003, 01:17  #321 
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Well, I would teach them algebra, but that doesn't fit into your rules. Anyone else know? I am really curious to see what the answer is.

27th March 2003, 01:22  #322 
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The number of heads is the number of animals.
Suppose it was 13 hens then there is an excess of 14 legs, which means we have 7 lots of 2 legs with which we can 'upgrade' 7 of the hens to goats, So there are 7 goats and (137) =6 hens. UJ 
27th March 2003, 01:24  #323 
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can a 7 year old count to 40?

27th March 2003, 01:35  #324 
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Let me rephrase the question, so that we may quickly end this (the original one is ambiguous  depending on how you interpret it, 50/50 could be correct):
You come up to a couple, and find out that they have two children. You ask, "Is one of those children a girl?". They respond, "yes". What is the likelihood of the other child being a boy? Note: If someone doesn't explain this correctly by tomorrow, I will. Freedom of speech is the basic freedom of humanity. When you've lost that, you've lost everything. 1\/\/4y 34<$p4y 1gp4y 33714y, 0d4y 0uy4y?  Roses are #FF0000; Violets are #0000FF; chown R ${YOU} ~/base The DMCA. It really is that bad. : Count for your life. 
27th March 2003, 01:55  #325 
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50/50. The sex of the other child is independent of the fact that one is a girl.

27th March 2003, 01:56  #326  
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Quote:
This how it was explained to me when I was 7. Imagine that the goats started walking on their hind legs and using their front legs as arms. Then there would be twice as many legs as there are heads. 26 legs. That leaves us with 14 former legs that became arms. There are 2 arms per goat so there are 7 goats. That leaves 6 heads that are chickens. I had so much fun imagining goats walking on their hind legs that I still remember it 20 years later. 

27th March 2003, 02:27  #327 
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rumata, nice. that is a very interesting method. neverthought of it that way.

27th March 2003, 02:45  #328 
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Me is confused  Goats walking on two legs???
JK, but that way seems really weird to me. I just like the algebra approach  short and sweet. 
27th March 2003, 18:31  #329 
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Phhff. The approach is basically the same.
goats = (legs(heads * 2))/2 and of course, hens = heads  goats Freedom of speech is the basic freedom of humanity. When you've lost that, you've lost everything. 1\/\/4y 34<$p4y 1gp4y 33714y, 0d4y 0uy4y?  Roses are #FF0000; Violets are #0000FF; chown R ${YOU} ~/base The DMCA. It really is that bad. : Count for your life. 
27th March 2003, 23:50  #330 
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i have a correct answer to this from when i was doing a probabilities course. i just really can't be bothered finding it. i remember some of the things.

28th March 2003, 00:01  #331  
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Quote:


28th March 2003, 01:10  #332 
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The point is that it is the same solution.
Freedom of speech is the basic freedom of humanity. When you've lost that, you've lost everything. 1\/\/4y 34<$p4y 1gp4y 33714y, 0d4y 0uy4y?  Roses are #FF0000; Violets are #0000FF; chown R ${YOU} ~/base The DMCA. It really is that bad. : Count for your life. 
28th March 2003, 01:24  #333 
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Well duh. Of course it's the same solution. Would be strange if this trivial problem were to demonstrate an incosistency between different branches of mathematics.

28th March 2003, 01:28  #334 
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That would be cool, but would require going into advanced mathematics to get something that would disagree.

28th March 2003, 01:40  #335 
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The answers are the same it's true, they must be, but goats = (legs(heads * 2))/2 is too compact and abstract for a 7 year old.
The whole thing can be turned around to give the following solutions (i) If all the animals were goats there would be 12 legs too many, so six of the goats have to lift their front legs in the air and pretend they are hens. If there are 6 hens there must be 7 goats. (ii) hens = ((heads*4)legs)/2 You have to admit the first is easier for a 7 year old to understand, even though the second says exactly the same as the first. Move on Someone post a riddle then. UJ 
1st April 2003, 08:16  #336  
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Well, looks like it's time for me to remind everyone that this thread exists.
Here's the "riddle" Quote:
Of course, by "one child", we mean we don't care what sex the other is. Otherwise, it's a 100% chance. Freedom of speech is the basic freedom of humanity. When you've lost that, you've lost everything. 1\/\/4y 34<$p4y 1gp4y 33714y, 0d4y 0uy4y?  Roses are #FF0000; Violets are #0000FF; chown R ${YOU} ~/base The DMCA. It really is that bad. : Count for your life. 

1st April 2003, 12:38  #337 
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depends on the form of the question and its interpretation.
http://mathforum.org/dr.math/faq/faq...rl.choose.html however the basic logic if choosing the family first is correct 
1st April 2003, 17:28  #338 
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Um... The question was explicitly stated, and the form of it's collection, too.
Freedom of speech is the basic freedom of humanity. When you've lost that, you've lost everything. 1\/\/4y 34<$p4y 1gp4y 33714y, 0d4y 0uy4y?  Roses are #FF0000; Violets are #0000FF; chown R ${YOU} ~/base The DMCA. It really is that bad. : Count for your life. 
1st April 2003, 17:35  #339 
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the likely hood of him being a boy is 49.5%.
49.5% chance its a boy, 49.5% chance it's a girl, and 1% chance its a hermaphrodite. (I mean, it either is a boy or it isnt,or it could be both.) 
1st April 2003, 18:27  #340 
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what if its a salmon? theyc an change their sex.

1st April 2003, 20:38  #341  
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Quote:
However, following your logic, it would mean at least a 50.5%, because a hermaphrodite would be a boy AND a girl, would it not? Let's see. If we took that into account... I calculate it at 67.5452829564% (roughly) Freedom of speech is the basic freedom of humanity. When you've lost that, you've lost everything. 1\/\/4y 34<$p4y 1gp4y 33714y, 0d4y 0uy4y?  Roses are #FF0000; Violets are #0000FF; chown R ${YOU} ~/base The DMCA. It really is that bad. : Count for your life. 

1st April 2003, 20:41  #342 
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HeyHey! I'm a "Major Dude"... (I just noticed this)
Freedom of speech is the basic freedom of humanity. When you've lost that, you've lost everything. 1\/\/4y 34<$p4y 1gp4y 33714y, 0d4y 0uy4y?  Roses are #FF0000; Violets are #0000FF; chown R ${YOU} ~/base The DMCA. It really is that bad. : Count for your life. 
1st April 2003, 21:24  #343 
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if it is either a boy, or a girl (no mix) then there is a 50% chance of either. Because it either is, or it isnt a boy, only 2 choices.
Btw, i was being silly with the hermaphrodite. 
1st April 2003, 21:46  #344 
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what is the question.
[size=0.1]The Durango 95 purred away real horrorshow, a nice warm vibratey feeling all through your guttiwuts[/size] 
1st April 2003, 22:12  #345  
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As for the hermaphrodite, um, DUH. CremoNe: Go up 8 posts for the question. Freedom of speech is the basic freedom of humanity. When you've lost that, you've lost everything. 1\/\/4y 34<$p4y 1gp4y 33714y, 0d4y 0uy4y?  Roses are #FF0000; Violets are #0000FF; chown R ${YOU} ~/base The DMCA. It really is that bad. : Count for your life. 

1st April 2003, 22:56  #346  
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Quote:
[size=0.1]The Durango 95 purred away real horrorshow, a nice warm vibratey feeling all through your guttiwuts[/size] 

1st April 2003, 23:17  #347 
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BG and GB are the same. Think of it in terms of money.
G = 0 cents B = 1 cent GG BG GB BB / 00 10 01 11 the BG GB both equate to 1 cent, and thus cancel each other out. "Of the 3 "yes" answers, two of the pairs of children have a boy." I can easly say that for the girl too. GG BG GB BB = 3 girls,1 boy GG BG GB BB = 3 boys, 1 girl 50/50 
1st April 2003, 23:47  #348  
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Quote:
Quote:


2nd April 2003, 01:48  #349  
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Clearly, you are all just not intelligent enough. Just kidding.
Ok, let's try and look at this another way.
Quote:
Quote:
Ok. That's basically the same argument (hopefully clarified), but it is the correct argument. If someone still disagrees, point out what's wrong. Freedom of speech is the basic freedom of humanity. When you've lost that, you've lost everything. 1\/\/4y 34<$p4y 1gp4y 33714y, 0d4y 0uy4y?  Roses are #FF0000; Violets are #0000FF; chown R ${YOU} ~/base The DMCA. It really is that bad. : Count for your life. 

2nd April 2003, 03:05  #350 
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what is wrong: Mathematicians are idiots (ok, they ain't, but in this case they are ). Strictly biologically speaking, the sex of an individual is completely independent of their siblings' sex. They are either a boy or a girl (assuming the baby is normal and healthy, and all that extra stuff . Therefore, the likelihood is 50/50. Math has no place in biology. 50/50 is the answer. I rest my case
/edit: ok, i just repeats what Rumata said....sry. /further edit: An example that is most likely a waste of my time: I flip a coin. What are the odds I get 'heads'? 50/50 right? I flip it again. Why should the odds of that flip be any different? Has a side been added? (no, it will not land on it's rim ) no. It's options are still heads and tails. The odds remain 50/50. 
2nd April 2003, 03:50  #351 
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another way of doing this not using sample spaces is with a probability tree
code: this shows that the probability of having a boy and a girl, regardless of the order of birth/selection, is 1/4+1/4=1/2. however, this only is true because there are two different paths to this result boy first, girl second and girl first, boy second now to the actual question. we know that out of 2 children, 1 is a girl, and we want to find the probability that the other is a boy. What we have now is a conditional probability, the probability tree now looks like this. code: This is because we know BB is not possible. Thefore there are 3 possibilities, 2 of which can be a boy. the probability of a boy given that there is a girl is: P(BG)=1/3 + 1/3 = 2/3 checkout this for more info: http://mathforum.org/dr.math/faq/faq.boy.girl.html This is similar to flipping coins. The chance of heads or tails is always 50%  ie every time u flip there is a 50 % chance of u getting heads or tails. However if out of 2 flips, (at least)one of them is a head, the other one is 2/3 likely to be tails and 1/3 likely to be heads. Its a bit freaky, but its because you don't know which flip the head came up on. If I tell you that my first flip is a head, then it is a 50/50 chance, because u know that the tailshead and tailstails options are gone. 
2nd April 2003, 03:51  #352 
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ok ok, i agree that there can be two answers.

2nd April 2003, 04:02  #353 
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hehe dlinkwit27, you used the same example as me, but with a different explanation!
You are right, if u flip, get a head, the next time is just as likely to be heads or tails However, if u flip twice, and tell me that one is a head  u could have flipped HH, HT, TH  this is different than the other situation as there is an extra possibility which increases the chances of tails , flipping tails on the first go, and heads on the second. This comparison is the same as whether u ask if one is a girl, or if the oldest is a girl. Trust me, statistics is not logical. 
2nd April 2003, 04:21  #354 
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The chance of flipping a coin and it landing on the rim is 1 in a trillion.

2nd April 2003, 06:51  #355  
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Biology has nothing to do with it. The other child is already born, and we are assuming 50/50 anyway.
Statistics is totally correct and logical (in this case, anyway). Quote:
Try it. Flip two coins several times. Check how many times you get HT or TH, as opposed to HH. You'll find it's more. About 2/3s of the time, you will get TH or HT, and the rest, HH. (This is ignoring any times that you get TT, which, of course, wouldn't count towards anything). Really, try it! Freedom of speech is the basic freedom of humanity. When you've lost that, you've lost everything. 1\/\/4y 34<$p4y 1gp4y 33714y, 0d4y 0uy4y?  Roses are #FF0000; Violets are #0000FF; chown R ${YOU} ~/base The DMCA. It really is that bad. : Count for your life. 

2nd April 2003, 18:13  #356 
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One coin is already flipped. you cant just change the sex of the girl at will. It's a girl and it will STAY a girl. you're only flipping one coin. The odds of it being a boy is just as equal of it being a girl. 50 fucking 50.

2nd April 2003, 21:22  #357 
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if you flip two coins X number of times, the change you get all heads is 1/4, you get all tails 1/4, and the change that you get a mix is 1/2. I still stand by my 2 answers though,

2nd April 2003, 21:57  #358  
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SSJ4_Gogitta, this is exactly what I'm talking about. You have not "flipped one coin"  because you don't know which coin I'm talking about. Let's say you have a hat. You've got the following written on 4 pieces of paper: GG GB BG BB You pull out one of them, have someone else look at it, and ask them "is one of the letters 'G'?"  they answer "yes". You do it again, until all 4 have been pulled out of the hat. You will find that of the 3 times that there was a 'G', the other letter was 'B'. Or is it that you don't think {GG, GB, BG, BB} is the correct distribution of Gs and Bs? Freedom of speech is the basic freedom of humanity. When you've lost that, you've lost everything. 1\/\/4y 34<$p4y 1gp4y 33714y, 0d4y 0uy4y?  Roses are #FF0000; Violets are #0000FF; chown R ${YOU} ~/base The DMCA. It really is that bad. : Count for your life. 

2nd April 2003, 22:23  #359 
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The answer is 50/50
IT WILL EITHER BE A BOY OR A GIRL. No inbetween. It eiter will, or it wont. Equal chances. And it dosent matter wich coin you filp, each coin has a 50/50 chance of being heads. And you DID flip one coin. The other one has already been flipped, and was tales. It is the other coin we are worried about. We KNOW for a 100% FACT that the first child is a girl. The odds of the 2nd child, the 2nd coin, of being heads is 50/50. It either will, or it wont. ockham's razor states that the simplest answer tends to be the correct one. ITS LOGIC. It either will, or it wont be a boy. And again with the GG GB BG BB thing. ITS BULLSHIT. the GB BG are THE SAME. one boy, one girl. it DOES NOT MATTER if the girl is on the left, or the right. it states the SAME THING. you have a boy and a girl. Whats left is GG BB. 50/50 chance of picking either. 
2nd April 2003, 22:30  #360 
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How about this. We eliminate the girl. the girl never existed.
We elimited a 100% chance of having a girl, so lets elimiate a 100% chance of having a boy. so GG BG GB BB narrows down to BG GB Now, waht are the odds of haivng a boy? 50/50. Now, say the first one IS a girl. Since there was a 50% chance of having a girl, there was a 50% chance of having a boy, there is no 100% chance of a boy. GG BG GB BB now narrows down to G BG GB B which is the same as GB GG BB since there are no 100% chances, it further reduces to: GB Now, it dosnet matter which one you pick, you still have a 50% chance of picking a boy. 

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