Moshe Gariani
Well-known member
- Mar 10, 2005
- 12,204
What is the probability that the other one is a boy?
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A man has two children. One of them is a boy.
- Thread starter Moshe Gariani
- Start date
To work this out you need to know the probability of having identical twins, and I can't be bothered to look that up.
And you also need to look up the probability any given child is a boy anyway. I doubt it is exactly 50:50 ( and may even vary from country to country ?
)
And you also need to look up the probability any given child is a boy anyway. I doubt it is exactly 50:50 ( and may even vary from country to country ?
)
Thunder Bolt
Silly old bat
1 in 3
- Aug 7, 2003
- 8,093
GOM
living vicariously
Zero, as one of them is a boy, so, the other can't be.
Perry's Tracksuit Bottoms
King of Sussex
A man has two children. One of them is a boy.
Need to define the question better - too many answers:
1). It's a trick question; men don't have children, women do.
2). Somewhere very close to 50/50.
3). Is there something nasty Jimmy Saville-like going on here?
Need to define the question better - too many answers:
1). It's a trick question; men don't have children, women do.
2). Somewhere very close to 50/50.
3). Is there something nasty Jimmy Saville-like going on here?
nwgull
Well-known member
Chances of the other child being an identical twin are approx. 3/100, otherwise it's 50/50. So approximately 51.5% chance that the other is a boy.
Although I fear I may have missed the trick part of this question.
Although I fear I may have missed the trick part of this question.
symyjym
Banned
Yes "One of them is a boy."
Blue Valkyrie
Not seen such Bravery!
"And so is the other" is a possible follow on line, and hence has a probability...
symyjym
Banned
What's the probability of it being a trick question?
Blue Valkyrie
Not seen such Bravery!
Arthritic Toe
Well-known member
Nope - don't buy that. That line contradicts the first line. So the answer is zero.
Blue Valkyrie
Not seen such Bravery!
So it's impossible for someone ever to say "one of my children is a boy.... and so is the other one" ?
brakespear
Doctor Worm
Nope - 'One of them is a boy' does not preclude the other child being a boy also - 'Only one of them is a boy' would though.
symyjym
Banned
Not sure, not enough data given
Even if it isn't meant to be a trick question, you would have to include the probablility of it being so, and then work out the probablility of it being a boy.
The questioner has failed if it wasn't a trick question.
Blue Valkyrie
Not seen such Bravery!
Even if it isn't meant to be a trick question, you would have to include the probablility of it being so, and then work out the probablility of it being a boy.
The questioner has failed if it wasn't a trick question.
Good point, you would need to factor this in.
mreprice
Active member
I think he means at least one of them is a boy. The question is effectively the probability he has two boys.
The answer to that question is 1 in 3 assuming the odds of a boy is 1/2 I.e ignoring identical twins and the fact 52% of babies are boys.
The answer to that question is 1 in 3 assuming the odds of a boy is 1/2 I.e ignoring identical twins and the fact 52% of babies are boys.