Seeing as this is currently breaking Facebook…

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.

Is the question actually answerable until you have determined that Beagles are actually born at an exact 50:50 ratio of female – male?

Safe to say, maths trumps all else.

Only if you use the correct maths.

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..

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

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?

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.

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.

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’.

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.

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.

I went past the local pet shop,the other day. They had a sale on.

All the budgies were going cheep.

IGMC .

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.

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?

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.

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

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.

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?

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.

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.

I’m impressed all of this is still going.

Surely it’s about semantics – how the question is asked.

The 50/50 explanation:

Man phones wife, and says “is one of those two dogs male?”

She says “yes.”

He asks “is the other one also male?”

Probability of her replying yes: 50%

(assuming dogs are equally likely to be born female as male)

The 1/3 explanation:

Man phones wife, and says “is one of those two dogs male?”

She replies “neither is female.”

Probability of both dogs being male: 1/3

(because there are 3 possible situations: dog A is male and B female, dog A is female and B male, dog A is male and B is male)

HTH.

She replies “neither is female.”

Probability of both dogs being male: 1/3

erm?

I’m impressed all of this is still going.

Surely it’s about semantics – how the question is asked.

<strong class=”bbcode-strong”>The 50/50 explanation:

Man phones wife, and says “is one of those two dogs male?”

She says “yes.”

He asks “is the other one also male?”

Probability of her replying yes: 50%

(assuming dogs are equally likely to be born female as male)

<strong class=”bbcode-strong”>The 1/3 explanation:

Man phones wife, and says “is one of those two dogs male?”

She replies “neither is female.”

Probability of both dogs being male: 1/3

(because there are 3 possible situations: dog A is male and B female, dog A is female and B male, dog A is male and B is male)

HTH.

was going to say clearest post yet til

She replies “neither is female.”

Probability of both dogs being male: 1/3

erm?

but yes, amend that to “theyre not both females” and its perfect?

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

It’s maths probability problem, and there is only one correct answer to the question “as is”.

Lots of people on this thread have explained the answer. You can find independent explanations of the problem elsewhere. You can easily simulate the problem yourself and actually check the outcome. The only reason to continue arguing against the correct answer, or to keep changing the original problem, is that it’s more important to convince yourself you are right than it is to understand something.

I didn’t get the correct answer when I first looked at it, but I read the explanations that people provided, reread the question and worked it through myself. Now I’ve learned (or relearned; it’s a long time since I studied any probability) something. There’s nothing wrong with being wrong if you learn from it!

This:

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.

reminds me, of this:

“Doublethink means the power of holding two contradictory beliefs in one’s mind simultaneously, and accepting both of them.”

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.

Was the question worded in such a way that it sounds similar to a logic puzzle, one that has a non-intuitive answer, but has been re-worded so that the intuitive answer is the correct one?

It was the bit about the bath that suckered me in.

I guess the original version was something like, ‘Hey, is that dog you’re bathing a boy or a girl?’

There are a lot of us here.

Some of which have returned from a year long slumber just to post on this thread.

It’s a good thread Drac

reminds me, of this:

One of favourite books!

Later that evening the man is washing his mountain bikes. What are the odds one is an e bike and the other is a rigid 29r?

Later that evening the man is washing his mountain bikes. What are the odds one is an e bike and the other is a rigid 29r?

On what day did he purchase the e-bike?

On what day did he purchase the e-bike?

Oh, you really don’t want to go down that road.  If this puzzle was confusing, that probability will break everyone’s head.

She replies “neither is female.”

Probability of both dogs being male: 1/3

(because there are 3 possible situations: dog A is male and B female, dog A is female and B male, dog A is male and B is male)

Perhaps I should have emphasised, probability of both dogs being male: 1/3. If they’re not female, they’re male (we’re assuming… let’s not get into trans politics!)

So probability of only one dog being male is 2/3 (2 out of the three situations I described with dogs A and B), probability of both/ (the 3rd situation) is 1/3.

Does that make more sense?

On what day did he purchase the e-bike?

The day that hell froze over!

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

I gave it a try at my local pet shop. They have an ant farm and pulled two out for me. Turns out there are hardly any female Beagles. Most are worker beagles but there are a few male beagles around July.

Don’t know if anyone has already linked to Marilyn vos Savant’s explanation?

https://en.wikipedia.org/wiki/Marilyn_vos_Savant#%22Two_boys%22_problem

The confusion arises here because the bather is not asked if the puppy he is holding is a male, but rather if either is a male. If the puppies are labeled (A and B), each has a 50% chance of being male independently. This independence is restricted when at least A or B is male. Now, if A is not male, B must be male, and vice versa. This restriction is introduced by the way the question is structured and is easily overlooked – misleading people to the erroneous answer of 50%.

Some of which have returned from a year long slumber just to post on this thread.

Hi! Long time listener, not very regular caller; occasional lurker. Actually got a notification because someone had sent me a message, then spotted this thread. 🙂

What is the probability that the <i>other</i> one is a male?

What is the chance there are two boys?

To me, these seem to be two different questions. The first question steers towards 50pc the second towards 33pc. I’m sure they’re not intended to be, but that’s how I read it.

I can’t help but think the arguments in this thread are more about English than maths.

I’m bored enough to have a go at explaining now. Will try to put it in ‘common sense’ terms for sbob’s benefit.

1. Man is talking to pet shop about 2 dogs. At this point in time he has no additional information.

2. This gives 4 possibilities for their genders, 2 for each dog. There’s a 50% chance the dogs are the same gender and 50% chance they’re different.

3. The pet shop owner’s wife then gives us an additional piece of information: 1 of the dogs is male.

4. This removes one of the 4 possibilities (both female) leaving us with 1/3 chance they’re both male.

It’s not about considering all the information at once or breaking it into steps. The only difference that makes is how you make sense of it in your own mind. You can skip the first 2 steps and the answer is the same. You can’t change the outcome of a demonstrable mathematical problem by thinking about it differently.

You can’t change the outcome of a demonstrable mathematical problem by thinking about it differently.

You can’t. But you can misunderstand the mathematical problem itself by assuming that your one way of interpreting it from the outset is the only correct one.

Read my post above with the two explanations. The two interpretations give situations that are two different mathematical problems:

One is basically “We have determined Dog A is male; what are the odds that Dog B is male?” Answer: 1/2.

The other is “We have determined that there are four equally possible outcomes and have eliminated exactly one. What is the probability that Dog A and B are both male?” Answer: 1/3