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Can I check I have the gist of the argument correct?

It's not about the maths, it's about whether the question is a linguistic trick or a slightly ambiguously worded maths puzzle?

I'd ask sbob to flip a coin a hundred times and pair the results, but he'd tell me he should actually be given a coin that's already heads and flip another one to see if it matches.


 
Posted : 16/11/2018 8:48 am
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I don't think the use of the word "also" changes the meaning in any way

"the other one being male" already refers to the one other than the one that has been determined to be male, thus is perfectly synonymous (in this context) with "the other one also being male".

One on my shoes is wet. If the other one is wet, then it is also wet.


 
Posted : 16/11/2018 9:04 am
 kcr
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It’s not about the maths, it’s about whether the question is a linguistic trick or a slightly ambiguously worded maths puzzle?

Yes, the original puzzle is a maths probability problem with a clear answer (albeit the answer is counterintuitive, hence the heated discussion). Some people who don't agree with the correct answer and explanations are attempting to justify wrong answers by arguing about language or answering different questions!


 
Posted : 16/11/2018 9:27 am
 Drac
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I don’t think the use of the word “also” changes the meaning in any way

No not at all it just makes it clearer for those that can’t grasp the original question. Me included when it first appeared on here waaaay back.


 
Posted : 16/11/2018 9:31 am
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I don’t think the use of the word “also” changes the meaning in any way

It certainly clarifies what the question is asking you, obviously if you read it correctly and understand the maths you get the correct answer. My problem when always doing these problems is that I know I am supposed to be tricked, get bored reading about puppies (I prefer playing with them) and skip to the end as I really am not bothered about getting it right or wrong.


 
Posted : 16/11/2018 10:41 am
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What might be an idea now, is to change the question so that everyone (might) get the same answer. Keep the original question the same, but make the probability of a male dog be 2/3 and female dog 1/3.


 
Posted : 16/11/2018 10:49 am
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What might be an idea now, is to change the question so that everyone (might) get the same answer. Keep the original question the same, but make the probability of a male dog be 0.666666 and female dog 0.333333

I'm slightly dissapointed with you given your username


 
Posted : 16/11/2018 10:56 am
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I’m slightly dissapointed with you given your username

Whilst this does not surprise me - I frequently disappoint. Could you explain further. And I didn’t use decimals, as that would not give the same answer ie 1/2.


 
Posted : 16/11/2018 11:04 am
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Gaussian distribution joke init? Yes that's where we are.

I'm genuinely disappointed no one's tried to explain the alternative solution using Bayes' Theorem. Which gives the same answer of course. It's straightforward logic, this isn't one where we get to vote.


 
Posted : 16/11/2018 11:13 am
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gaussian distribution joke init? Yes that’s where we are

Hmm, I’m more of an admirer of Gauss than a peer. Somewhat out of my comfort range, but I’d still chose fractions over decimals in most situations, as a preference.


 
Posted : 16/11/2018 11:21 am
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I’m genuinely disappointed no one’s tried to explain the alternative solution using Bayes’ Theorem. Which gives the same answer of course. It’s straightforward logic, this isn’t one where we get to vote.

Whilst I’ve heard of Bayes’ theorem, I know nothing more about it than:

Bayes' theorem is a formula that describes how to update the probabilities of hypotheses when given evidence.

So I had a quick look online and the first site I looked at  https://brilliant.org/wiki/bayes-theorem/  does just that. Quelle surprise 1/3.


 
Posted : 16/11/2018 11:43 am
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Hah, that page even uses the same example.

We might reason as follows: “We know that one is a boy, so the only question is whether the other one is a boy, and the chances of that being the case are 50%. So again, the answer is 50%"

This makes perfect sense. It also happens to be incorrect.


 
Posted : 16/11/2018 11:57 am
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How many children does the woman who's bathing puppies have?


 
Posted : 16/11/2018 12:06 pm
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The main thing conveyed by this thread is just how far people will go to not "lose" an argument. Inverted commas 'cause learnin' ain't losin'.


 
Posted : 16/11/2018 12:06 pm
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When will this be finished?

I’ve got a fiver each way on the Beagle in trap 2.

Got good odds .....3/2


 
Posted : 16/11/2018 12:16 pm
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Guys I may not be an egghead maths guy like you lot but listen, I’ve got plenty of qualifications in common sense from the university of life and here’s my take...

the wife picks up the male dog

there is one dog left

that dog has a 50/50 chance of being a male.

Answer is 50% - qed end of thread

hope this helps some of you


 
Posted : 16/11/2018 12:29 pm
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that's answering a different question.

anyway... which one is the Nazi? The shopkeeper or the one washing the dogs?


 
Posted : 16/11/2018 12:43 pm
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We know one is a Beadle of the male variety. What’s the odds of the other one also being a male Beadle?


 
Posted : 16/11/2018 12:45 pm
 sbob
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The 1/3ers cannot cope with applying all their information at once, as garnered from the question.

They would be the people looking at the ever decreasing steps taken by Achilles in Zeno's famous paradox completely failing to realise that the tortoise would be overtaken.


 
Posted : 16/11/2018 12:50 pm
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You can keep your paradox pal

all I know is, a man rings his wife and asks her if she’s holding a dog. She says yes, it’s a boy. He then asks her what the other dog is and she replies that it’s 50% a boy too.


 
Posted : 16/11/2018 12:55 pm
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Whilst this does not surprise me – I frequently disappoint. Could you explain further. And I didn’t use decimals, as that would not give the same answer ie 1/2.

Because in all honesty* i read it as 1 in 3 which isn't a probability.

I was trying to be smart and itbackfired what is the probability of this occuring again ...

*Words are hard


 
Posted : 16/11/2018 12:59 pm
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What’s the odds of the other one also being a male Beadle?

On the one hand, quite large, on the other.....😉


 
Posted : 16/11/2018 1:02 pm
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Guys I may not be an egghead maths guy like you lot but listen, I’ve got plenty of qualifications in common sense from the university of life and here’s my take…

I’m sorry, but all your qualifications in common sense (I’m not sure there actually is such a thing) aren’t worth the paper they’re not written on.

Safe to say, maths trumps all else.

It’s one thing to not be a “maths egghead”, but to argue with people who know what they’re talking about, doesn’t holler much sense at all.


 
Posted : 16/11/2018 1:03 pm
 Drac
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On the one hand, quite large, on the other…..😉

Dead uncertain.


 
Posted : 16/11/2018 1:08 pm
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The 1/3ers cannot cope with applying all their information at once, as garnered from the question.

Go on then. I'll bite one more time. Where is the flaw here:

You have let's say 10,000 pet shops in your town. Each with a random number of dogs of a random distribution of genders.

For example there will be approximately 100 shops with 1 dog, split roughly 50 M, 50 F. There will be approximately 100 shops with 2 dogs split roughly 25 MM, 50 MF, 25 FF. There will be approximately 100 shops with 3 dogs split 12 MMM, 38 MMF, 38 MFF, 12 FFF and so on... Do you agree this is a fair random distribution?

We only care about shops with two dogs where one is a male. That is 75 shops out of the 10,000. If you randomly phone one of those shops what is the probability that they have 2 males? Pretty clearly there are 25 shops with 2 males so 25/75 or 1/3


 
Posted : 16/11/2018 1:08 pm
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The 1/3ers cannot cope with applying all their information at once, as garnered from the question.

They would be the people looking at the ever decreasing steps taken by Achilles in Zeno’s famous paradox completely failing to realise that the tortoise would be overtaken.

Or, more likely the ones who know how to sum an infinite geometric series!

This is starting to get irritating now. Do any of the 50%ers have an area/topic on which they know what they’re talking about. I’d like a go at coming along and talking shite.


 
Posted : 16/11/2018 1:10 pm
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Is the question actually answerable until you have determined that Beagles are actually born at an exact 50:50 ratio of female - male?


 
Posted : 16/11/2018 1:11 pm
 sbob
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Safe to say, maths trumps all else.

Only if you use the correct maths.


 
Posted : 16/11/2018 1:11 pm
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wow is this still rumbling on, i thought it was decided yesterday that the second dog is male is 50:50

but the probability of both dogs being male is 1 in 3 (as no FF option as we know one is a male)..

it all depends how you read the question and if you feel the other dog is dependent or independent of the outcome..


 
Posted : 16/11/2018 1:13 pm
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Is the question actually answerable until you have determined that Beagles are actually born at an exact 50:50 ratio of female – male?

Yes, but you need to know the ratio to get a value. 50:50 gives 1/3


 
Posted : 16/11/2018 1:20 pm
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Because in all honesty* i read it as 1 in 3 which isn’t a probability.

Why not?

What is wrong with the probability of rolling a 5 on a fair, standard, 6 faced die, being 1/6?


 
Posted : 16/11/2018 1:26 pm
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wow is this still rumbling on, i thought it was decided yesterday that the second dog is male is 50:50

but the probability of both dogs being male is 1 in 3 (as no FF option as we know one is a male)..

Whoa there! What are you doing with the being sensible? I’m trying to get this bad boy to 20 pages.


 
Posted : 16/11/2018 1:27 pm
 sbob
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The fact of the matter remains that there are two dogs; one male, one male or female. There is no point in talking about a female dog that does not exist in the question.


 
Posted : 16/11/2018 1:34 pm
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wow is this still rumbling on, i thought it was decided yesterday that the second dog is male is 50:50

but the probability of both dogs being male is 1 in 3 (as no FF option as we know one is a male)..

it all depends how you read the question and if you feel the other dog is dependent or independent of the outcome..

Arghh! There is no ‘second dog’.


 
Posted : 16/11/2018 1:37 pm
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The fact of the matter remains that there are two dogs; one male, one male or female. There is no point in talking about a female dog that does not exist in the question.

In your world this might be the case. That is to say a construct which has be colluded to ensure the series of events described is the only possible outcome to the point in the 'story' where the wife answer yes with the only probability left to consider is the final play.

I think your view of the problem is flawed. I can see how you could hold it, but don't think it rational. Your engineering of the scenario to ensure that the outcome is the same no matter how many times is plays out alters the probability irrevocably.


 
Posted : 16/11/2018 1:47 pm
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There are a lot of us here.

each of us phone the local pet shops until we find one which has 2 of one particular breed of animal.

Report back here the sex of each

should prove it once and for all.


 
Posted : 16/11/2018 1:57 pm
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I went past the local pet shop,the other day. They had a sale on.

All the budgies were going cheep.

IGMC .


 
Posted : 16/11/2018 1:59 pm
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Well, given the fact that this thread is at 14 pages and counting, trying to argue and reason this out seems to be working really well.

TIME FOR EXPERIMENTATION!!!

Take a deck of playing cards and remove all the cards for two of the suits.

This will leave you with 13 cards represented by your girl suit (for arguments sake, let's say hearts) and your boy suit (spades)

1. Shuffle the 26 cards and deal two cards, the first one face up

2. If the card is a heart (girl), return the cards to the deck and shuffle again

3. If the card is a spade (boy), turn the next card face up

4. Make a note of whether the 2nd card is a boy or girl

5. Repeat until you get bored

I did the above 30 times and my results were:

18 girls, 12 boys

If everyone does this a few times and logs their results we can keep a running total.  If the 50% people are correct the numbers should converge back to an even distribution pretty quickly.  If the 1/3 people are correct the numbers should swing the other way.


 
Posted : 16/11/2018 2:01 pm
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I went past the local pet shop,the other day. They had a sale on.

It’s a wonder it didn’t blow away...... or is that the paper shop?


 
Posted : 16/11/2018 2:03 pm
 sbob
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I'm doing the opposite of engineering the scenario, I'm looking at the question as is.

The 1/3rd answer is the engineered dissection.

As I said earlier, this isn't about the maths, it's about how one's brain deals with information. On one hand there is a group assessing all the information at once, on the other there is a group that has to break down the information to make sense of it.
You have: if dog 1 = M, then dog 2 = M or F coupled with If dog 1 = F, then dog 2 = M, giving the three options.

or

You have a dog which is male and the other that is male or female.

I can quite easily see how the former is more attractive to a certain type.


 
Posted : 16/11/2018 2:04 pm
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1. Shuffle the 26 cards and deal two cards, the first one face up

2. If the card is a heart (girl), return the cards to the deck and shuffle again

Nope, this is still broken logic.  You're arbitrarily assigning "male" to the first card / dog.  The second card / dog could be male and it would meet the criteria in the puzzle but you've just rejected it.

1. Deal both cards face up.

2. If both cards are hearts (girls), return the cards to the deck and shuffle again


 
Posted : 16/11/2018 2:07 pm
 sbob
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TIME FOR EXPERIMENTATION!!!

Your experiment is as flawed as the earlier coin toss suggestions. They both produce results that do not fit in with the question therefore are not valid.


 
Posted : 16/11/2018 2:10 pm
 sbob
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2. If both cards are hearts (girls), return the cards to the deck and shuffle again

I suppose you think we should be having a second referendum, you know, until we get the result that we want?


 
Posted : 16/11/2018 2:11 pm
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As I said earlier, this isn’t about the maths, it’s about how one’s brain deals with information.

You're not wrong there.

The whole point is that the solution is counter-intuitive.  The question then becomes whether you can override your gut feelings in the face of explanations and facts, or whether you doggedly cling to what "feels right" and start twisting the original premise to make it fit.


 
Posted : 16/11/2018 2:12 pm
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I suppose you think we should be having a second referendum, you know, until we get the result that we want?

We had a second referendum in 2016.


 
Posted : 16/11/2018 2:13 pm
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