The boy-girl puzzle

When will it get to 10…

When you post 🙂

Mboy please show me in the question where it specifically asks us to determine the chances of the woman having had the children in a specific order.

avdave2 – Member

Mboy please show me in the question where it specifically asks us to determine the chances of the woman having had the children in a specific order.

It doesn’t!

My point entirely…

What’s your point?

Mboy please show me in the question where it specifically asks us to determine the chances of the woman having had the children in a specific order.

Exactly why it’s 66% something I couldn’t understand at first.

Blimey, I can’t believe I’ve been away for the weekend and not only is this thread is still ticking along, but Smee seems to be gaining supporters like some kind of strange cult leader.

A few of the more interesting replies:

avdave2: Under current discrimination laws… 50% seems to be the politically correct answer.

Nah you’d still be discriminating on sex. You’d be safer saying you were 100% that they were a person – though obviously ethereal lifeforms should also have equal rights. 🙂

Junkyard: Don’t know or care whether any of this is correct just going for the 10 pages and will argue with you if it help GrahamS

I think Smee is doing enough trolling for everyone on this thread!

avdave2:please show me in the question where it specifically asks us to determine the chances of the woman having had the children in a specific order.

It doesn’t. But it is the reason why there are twice as many “boy and girl” combinations as there are “girl and girl”. In the initial population, 25% will be “two boys”, 50% will be “girl and boy”, 25% will be “two girls”.

Smee:The only idiocy that is going on is people not realising that both solutions are correct…..

For the question that I gave there is only one correct answer and that is 66.666..%

That is not really debatable. You can go and physically count the results on that spreadsheet and it comes to 66%. If you don’t trust the spreadsheet you can replicate the experiment yourself using coins and it is 66%. You can even do what Marilyn vos Savant did when she ran a poll of her readers and, with 18,000 replies, it came out almost exactly at 66%.

You might not like or understand the reasoning, but the result is not debatable.

I’m sure 50% is the “correct solution” to many interesting questions, but just not this one.

I notice that you still haven’t replied what you think the correct values are for your earlier post:

Out of the 4 combinations you have all ruled out boy/boy.

That leaves

girl/boy
boy/girl
girl/girl

show me how to figure out the probability that the first one is a boy…

I said 33% and explained why. I think you said 50% for each of them, but failed to explain why your probabilities added up to 150%.

Is this post still going?!

Yes.

Carry on then…

It’s Smee’s ball.

I think he’s took it home.

Play cancelled due to snow?

Nah! He’s just gone home.

You got much at Wylam often do they because it’s location?

Who cares?

Me that’s why I asked.

You got much at Wylam often do they because it’s location?

Yes snow some often do location is 😛

Actually I’m working up in Edinburgh this week. I think we actually got a fair bit in Wylam last night, but yeah it is pretty low lying so we’re not likely to be too badly affected. (Not sure if I’ll be taking the A68 home though – I suspect going through the Pennines would be fun!)

I would have thought STW would have gone home by now as well. Any people still in the office? Anyone?

i got to page 6 and then realised the answer 0.666666 is being explained very badly

g/b and b/g ARE the same or interchangeable. i would’ve thought that’d be obvious to everyone on here. it’s the MIXED option – it dosen’t matter which way round they are.

that leaves 3 options:

mixed
girl/girl
boy/boy

she’s already told you one’s a girl so that eliminates boy/boy.

so that leaves 2/3 options and here’s the bottom line….

2/3 = 0.6 recurring!!

And that’s your answer folks, none of this 2:1 bullshirt.

Yes snow some often do location is

lol! God damn it my dyslexia really shines through when I’m on nights.

WOW! Bomberman has some how made it even more confusing.

i got to page 6 and then realised the answer 0.666666 is being explained very badly

g/b and b/g ARE the same or interchangeable. i would’ve thought that’d be obvious to everyone on here. it’s the MIXED option – it dosen’t matter which way round they are.

that leaves 3 options:

mixed
girl/girl
boy/boy

she’s already told you one’s a girl so that eliminates boy/boy.

so that leaves 2/3 options and here’s the bottom line….

2/3 = 0.6 recurring!!

And that’s your answer folks, none of this 2:1 bullshirt.

Right answer, wrong reasoning 🙂

Yep – what mike said.

the question asks what are the chances of her having a mixed pair.

mixed
girl girl
boy boy (eliminated)

two options left therefore chances of mixed = 1/2 = 0.5

50 percent. 50/50.

a one in two chance, since she eliminated the boy/boy option.

the question asks what are the chances of her having a mixed pair.

mixed
girl girl
boy boy (eliminated)

two options left therefore chances of mixed = 1/2 = 0.5

50 percent. 50/50.

Nope.

yep

There’s a 2 in 3 chance, so 66%

no there isn’t a 2 in 3 chance, because there were only 3 options to start off with and one has been knocked out so it’s now down to a one in two chance

Dear God. How can you have read up to page 6 and come to that conclusion?

Just because there are two options DOES NOT MEAN that they are 50/50.

If there are 4999 girls and 1 boy in a room and I pick a child at random then the odds ARE NOT 50/50 that I pick the boy – despite the fact that yes, there are only two outcomes and yes, when the children were born it was 50/50 whether they were boy or girl.

For the sake of some people on here’s sanity, I’d just like to don my “Mark & Lard” voice and ask for a STOP………………

Carry on…………..

😉

youre muddling the issue grahamS
the question asks “what are the odds that she has one boy and one girl?”

you’ve got only 2 options left, one of which is MIXED

if someone puts a red ball and a blue ball in a bag, the chances of pulling out either are 50/50. Its simple and i dont know why youre adding in all the other stuff

if someone puts a red ball and a blue ball in a bag, the chances of pulling out either are 50/50. Its simple and i dont know why youre adding in all the other stuff

It’s not the same.

it is the same. two options left girl/girl, girl/boy. write them down on a peice of paper, put them in a bag, pick one out. what are the chances of you picking the mixed pair? 50/50.

grahamS the chances of you picking the boy in the room is 1/5000 or 0.02%

if someone puts a red ball and a blue ball in a bag, the chances of pulling out either are 50/50.

Not if there are more red balls than blue balls it isn’t!

And that is exactly what is happening here.
There are twice as many “mixed” as there are “two girl”.

If you started with 100 of these families then 25 of them would be two boys, 50 would be mixed and 25 would be two girls. If you then eliminate the 25 with two boys then you are 50 mixed and 25 with two girls. Pick one of them at random and you have a 2:1 (aka 66% aka 2/3) chance that it is a mixed family.

bomberman, there are three options left.

If you write “boy/girl”, “girl/boy” and “girl/girl” on three bits of paper and pick out one randomly, what is the chance of you getting one of the two with a boy on it?

no there arent twice as many mixed you CRETIN. girl/boy is the same as boy/girl. if someone asks you how many kids youve got it dosent matter wether you say “a girl and a boy” or “a boy and a girl” there are two ways of saying it but they both mean the same thing YOU PENARSE

it is the same. two options left girl/girl, girl/boy. write them down on a peice of paper, put them in a bag, pick one out. what are the chances of you picking the mixed pair? 50/50.

Write these on a piece of paper: “GG”, “GB”, “BG”, “BB”
These are the FOUR starting options.
Put them in a bag and pick one.
What are your chances of picking a mixed pair versus GG?

GB and BG are the same, so only count as ONE OPTION

no there arent twice as many mixed

Yes there are. Look. there’s two, count them.

girl/boy is the same as boy/girl

No it’s not.

if someone asks you how many kids youve got it dosent matter wether you say “a girl and a boy” or “a boy and a girl” there are two ways of saying it but they both mean the same thing

I’ve got two girls.

You’re wrong, but feel free to be shouty and abusive some more. You’ll still be wrong.

Go back and look at the tree diagrams again. There are three routes to the ‘finish’, two of which are one boy and one girl. Two out of three…

no there arent twice as many mixed you CRETIN. girl/boy is the same as boy/girl.

Yes, yes there are. really. Even Smee accepts this FFS.

Okay let’s start with 100 parents and no children, okay?
In this puzzle the chances of boy or girl being born are exactly 50/50.

So if those 100 parents all have ONE child then we will have:
50 families with a girl and 50 families with a boy.

Agreed?

Now if the 50 families who have a girl all then have a second child, then they will be split into 25 families with two girls and 25 families with a girl and a boy.

Likewise if the 50 that had boy then have a second child, then they will be split into 25 with two boys and 25 with a boy and a girl.

So the 100 families now look like:
25 with two girls, 50 mixed, 25 with two boys.

400 ???