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Offline  Cougar
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... and we've not had a plane on a treadmill for a while:

A man sees a sign in a window advertising two Beagle puppies for sale. He goes in and tells the shopkeeper he will only take the puppies if there’s at least one boy.

The shopkeeper phones his wife who is bathing the dogs and asks her if there’s at least one boy. She says yes.

What is the chance there are two boys?

 
Posted : 14/11/2018 10:27 pm
Offline  eddiebaby
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If they are dogs then 100% certain. If there are bitches though...

 
Posted : 14/11/2018 10:32 pm
Offline  funkmasterp
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Must......be........trick.......

50% unless she’s bathing different dogs.

edit - who gives a shit, the buyer is happy as he’s got what he wants already.

 
Posted : 14/11/2018 10:33 pm
Offline  sockpuppet
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Is it 1/3?

 
Posted : 14/11/2018 10:33 pm
Offline  sockpuppet
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Four options, boy-boy, boy-girl*, girl-boy*, girl-girl.

information supplied rules out one option, chance of two boys is this one out of the three remaining options.

1/3.

*these are different.

 
Posted : 14/11/2018 10:36 pm
Offline  lister
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Twelfty baby robins?

 
Posted : 14/11/2018 10:37 pm
Offline  matt_outandabout
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Which is the trans dog?

 
Posted : 14/11/2018 10:37 pm
Offline  earl_brutus
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It could be any of the following options

both dogs are male

one dog is male and one dog is female

So 50% chance.

 
Posted : 14/11/2018 10:38 pm
Offline  ajantom
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Not seen this problem, but seems simple....probability is 1/3....I think.

Edit....yep....

Original options are:

X=Male, Y=Male

X=Male, Y=Female

X=Female, Y=Male

X=Female, Y=Female

Option 4 is out, so 1 in 3.

 
Posted : 14/11/2018 10:38 pm
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The chance of being male is 50:50 the gender of the other one doesnt affect it.

 
Posted : 14/11/2018 10:39 pm
Offline  convert
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1/3 unless there is a trick. Puppies can't be boys as boys are ikle humans?

 
Posted : 14/11/2018 10:39 pm
Offline  rene59
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2/3

 
Posted : 14/11/2018 10:40 pm
Offline  sadexpunk
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It could be any of the following options

both dogs are male

one dog is male and one dog is female

So 50% chance.

after reading all the posts so far im going with this one...... (thats after an initial thought of 75%)

 
Posted : 14/11/2018 10:40 pm
Offline  funkmasterp
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Genuine question - How can it be 1/3? Surely the chances of it not been either a boy or girl are so slim as to be negligible? I’m missing some sort of weird mathematical shit aren’t I?

 
Posted : 14/11/2018 10:40 pm
Offline  athgray
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As said if she is bathing the dogs in question, and there are only two of them, then with the information surely the chance both are boys is 50%

She has confirmed at least one dog is a boy. The other dog can only be a boy or a girl. 50/50.

It cant be that simple can it????

 
Posted : 14/11/2018 10:41 pm
Offline  Cougar
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I should clarify that for the sake of argument, there's no trick here involving differences in birth rates; terminology of dogs vs bitches; terminology of words like "boy" when dogs aren't boys; gender-fluid beagles or any other random gittery.

 
Posted : 14/11/2018 10:43 pm
Offline  convert
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Genuine question – How can it be 1/3? Surely the chances of it not been either a boy or girl are so slim as to be negligible? I’m missing some sort of weird mathematical shit aren’t I?

Sockpuppet has a good explanation above.

 
Posted : 14/11/2018 10:43 pm
Online  lunge
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50/50, th sex of th first dog is irrelevant to the equation now it’s known.

 
Posted : 14/11/2018 10:44 pm
Offline  convert
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th sex of th first dog is irrelevant to the equation now it’s known.

The wife did not state which of the two dogs she was talking about.

 
Posted : 14/11/2018 10:46 pm
Offline  rene59
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Is this not the same as the deal or no deal thing/monty hall problem? If it is then I still won't understand it.

 
Posted : 14/11/2018 10:46 pm
Offline  eddiebaby
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*these are different.

Not in this case surely. Only 2 options for the other non defined as male dog.

 
Posted : 14/11/2018 10:47 pm
Offline  vongassit
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His wife & 2 dogs in the bath  : )

 
Posted : 14/11/2018 10:47 pm
Offline  ajantom
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50/50, th sex of th first dog is irrelevant to the equation now it’s known.

Yes, but either dog could be either sex. Adds another option.

 
Posted : 14/11/2018 10:47 pm
Offline  johnx2
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Someone will be faster. The question is about a pair of pups. We already know something about the pair - one is male.

Gah. Sock puppet explains it perfectly but I'll do it again anyway as that's what I do. Possibilities are MM, FM, MF, FF, equal one in four possibility of each, until we learn that one is M. So we then  know it can't be FF, meaning chances of MM become one in three. The end.

 
Posted : 14/11/2018 10:47 pm
Offline  feed
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Same as flipping a coin, if you flip once and it's heads, logically the chance of the second flip being heads is still 50:50 but by the laws of probability the chance of the second flip being heads is reduced.

 
Posted : 14/11/2018 10:48 pm
Offline  lucky7500
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Genuine question – How can it be 1/3? Surely the chances of it not been either a boy or girl are so slim as to be negligible? I’m missing some sort of weird mathematical shit aren’t I?

Sockpuppet has a good explanation above.

The question states that one is definitely a boy though. I'd agree with the 50%.

 
Posted : 14/11/2018 10:48 pm
Offline  earl_brutus
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MF and FM are one and the same so do not count twice.

 
Posted : 14/11/2018 10:48 pm
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X=Male, Y=Male

X=Male, Y=Female

X=Female, Y=Male

X=Female, Y=Female

??? Eh??Female wont make Y eggs, females dont have Y chromosomes.

So all female eggs are X 50% sperm Y to make a dog, 50% X to make a bitch.

 
Posted : 14/11/2018 10:49 pm
Offline  convert
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The question states that one is definitely a boy though.

The question states one, but not which one. It matters.

 
Posted : 14/11/2018 10:50 pm
Offline  funkmasterp
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MF and FM are one and the same so do not count twice.

Exactly this and why sockpuppets explanation didn’t make sense to me regardless of it being well written and reasonable. We already know one is a boy, so that just leaves 50/50. No amount of mathematical jiggery pokery will convince my simple mind otherwise.

The question states one, but not which one. It matters.

How (genuinely)? That dog, whichever one it is, is now out of the equation.

 
Posted : 14/11/2018 10:53 pm
Offline  sadexpunk
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Possibilities are MM, FM, MF, FF, equal one in four possibility of each, until we learn that one is M. So we then  know it can’t be FF, meaning chances of MM become one in three. The end.

but thats not the possibilities is it, as MF is the same as FM?

EDIT:  typing at the same time, great minds funkmaster 😉

 
Posted : 14/11/2018 10:54 pm
Offline  docgeoffyjones
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Genuine question – How can it be 1/3? Surely the chances of it not been either a boy or girl are so slim as to be negligible? I’m missing some sort of weird mathematical shit aren’t I?

The question does not give enough info to know which dog is the boy, so there are four out comes.

.....the plane takes off.

 
Posted : 14/11/2018 10:54 pm
Offline  athgray
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Imagine the dogs have stickers on prior to washing. Options are :-

Dog A                                 Dog B

Girl                                      Girl

Boy                                     Girl

Girl                                      Boy

Boy                                     Boy

If the wife confirms Dog A is a boy there are only 2 possible solutions. (50/50)

See below if she confirms dog B is a boy

Dog A                                 Dog B

Girl                                      Girl

Boy                                     Girl

Girl                                      Boy

Boy                                     Boy

Again this time if the wife confirms Dog B is a boy, there are still only 2 possible solutions (50/50)

It does not matter which dog the wife confirms is a boy. We can assume that the only options we have is that there are 2 boys OR 1 boy and 1 girl.

Same if I go to work knowing I have 2 children, but during the day I forget their sexes so I phone home to the wife.

Me 'Can you tell me if one of my children is a son?'

Wife 'Yes'

From that I can only either have a son and a daughter OR two sons. To have a son and a daughter is EXACTLY the same option as to have a daughter and a son.

 
Posted : 14/11/2018 10:55 pm
Offline  convert
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MF and FM are one and the same so do not count twice.

So if the wife had not been asked a question - what do you think the odds of there being one female and one male puppy were?

 
Posted : 14/11/2018 10:55 pm
Offline  rene59
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Not seen this problem, but seems simple….probability is 1/3….I think.

Your answer is straight out of the blog the puzzle came from.

 
Posted : 14/11/2018 10:57 pm
Offline  whatyadoinsucka
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If the dog and it’s kennel costs £110 and the dog costs £100 more than the kennel, how much is the kennel on it’s own

 
Posted : 14/11/2018 10:58 pm
Offline  funkmasterp
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typing at the same time, great minds funkmaster

High 5 sadexpunk. If we’re wrong (which we probably are) then I can categorically state I’m glad to be shite at maths 😀

 
Posted : 14/11/2018 10:58 pm
Offline  convert
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Please tell me some of you lot didn't take maths beyond O'level/GCSE 🙂

 
Posted : 14/11/2018 10:58 pm
Offline  docgeoffyjones
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but thats not the possibilities is it, as MF is the same as FM?

Imagine two dogs sitting in front of you. you do not know their genders what are the possible combinations of gender?

Left dog being a girl and right dog being a boy is not the same as right dog being a girl and left being a boy.

 
Posted : 14/11/2018 10:58 pm
Offline  ajantom
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50/50 is the 'logical' conclusion, but it's wrong. Honest 😉

Detailed explanation (or spoiler if you prefer) here:

https://scienceblogs.com/evolutionblog/2006/12/28/a-probability-puzzle-part-two

 
Posted : 14/11/2018 11:00 pm
Offline  funkmasterp
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So if the wife had not been asked a question – what do you think the odds of there being one female and one male puppy were?

But she was asked, so the odds changed.

Anybody have a rocking chair, a corner and a dunce hat I can borrow?

 
Posted : 14/11/2018 11:00 pm
Offline  sadexpunk
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So if the wife had not been asked a question – what do you think the odds of there being one female and one male puppy were?

not clever enough to tell you, but thats a different puzzle.  she has been asked and it makes a difference.  theres one dog left that we dont know the sex of, so 50%.

EDIT:  funkmaster again!! 😀

 
Posted : 14/11/2018 11:01 pm
Offline  funkmasterp
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This is like those Look Around You maths questions.

 
Posted : 14/11/2018 11:02 pm
Offline  eddiebaby
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But if you put them in a sack and say one is male? It’s like Schrodinger’s Dog.

 
Posted : 14/11/2018 11:02 pm
Offline  johnx2
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Exactly. If I told you I'd tossed a coin twice, and asked what are the odds l'd tossed heads both times, you'd say "one in four". That's because there are equal chances I'd tossed heads then tails, tails then heads, heads then heads, or tails then tails. So odds of heads then heads is one in four.

But if I asked the same question again and told you that one of the tosses was a head, you'd know that I hadn't tossed tails then tails. So odds of heads then heads are one in three.

Pretty clear? Or a lot of toss? Surely by now someone will have gone through the Bayes' Theorem way if doing this...

 
Posted : 14/11/2018 11:03 pm
Offline  sadexpunk
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Imagine two dogs sitting in front of you. you do not know their genders what are the possible combinations of gender?

Left dog being a girl and right dog being a boy is not the same as right dog being a girl and left being a boy.

thats not what we're faced with here, accept the puzzle for what it is, we dont have to imagine anything, we're told one dog is a male, we're left with one dog!  it cant be anything other than 50%!  surely? 😀

 
Posted : 14/11/2018 11:03 pm
Offline  earl_brutus
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I only work on logic

 
Posted : 14/11/2018 11:04 pm
Offline  earl_brutus
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This is a subtle but different question. The order in which the dogs are sat is now relevant.

 
Posted : 14/11/2018 11:05 pm
Offline  sadexpunk
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just (half) read the answer in that link, but its going on the 4 possibilities again, FM and MF being different etc.  so its a flawed answer.  i hope.

 
Posted : 14/11/2018 11:06 pm
Offline  funkmasterp
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Jean is shorter than Brutus but taller than Imhotep. Imhotep is taller than Jean, but shorter than Lord Scotland. Lord Scotland is twice the height of Jean and Brutus combined but only one-tenth of the height of Millsy. Millsy is at a constant height of x − y. If Jean stands exactly one nautical mile away from Lord Scotland, how tall is Imhotep?

 
Posted : 14/11/2018 11:06 pm
Offline  rene59
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Are chance and probability the same?

The OP asks what is the chance, so is the chance 1/2 but the probability is 1/3?

 
Posted : 14/11/2018 11:07 pm
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