An acquaintance tells you she has two children and you remember that one of them is a boy. Assuming every birth has an equal change of being male or female and you have no additional information about the children, what are the chances that the other child is also a male?
BTW, I'll be gone for a few days. In the meantime, please check out the rest of the site for more riddles, puzzles and other math/stat problems.
In my case it's 100%, but in reality it is still 50-50, the first one being male has no bearing on the second one.
ReplyDeleteI agree with Sean. 50/50
ReplyDeletewhere you going for a few days?
The probability to 2 child combinations are:
ReplyDeleteMM 25%
MF 50%
FF 25%
we are now told that this pairing has one male, so we can discount FF.
remaining probabilities are:
MM 33%
MF 67%
the probability of the 2nd child being Male is 33%
---
the reason people opted for 50% is that they read the question as:
'if child A is male, what is the probability of child B being male?'
in the case, the probabilities are:
MM 25%
MF 25%
FM 25%
FF 25%
with child A being male, we are left with:
MM 50%
MF 50%
and the chance of child B being male is 50%
the actual question said 'at least ONE of the children is male', meaning it could be A *or* B.
Male or not, they are children.
ReplyDeleteIn my experience girls are harder to raise.
Have you ever tried combing the hair of a 3 year old girl? Or get her to wear a dress for a special occasion?
I have a boy.
From where I come from, boys are relatively harder to raise when they're toddlers as they are harder to control. But as they grow older, it gets easier.
ReplyDeleteParents tend to be more protective of girls especially beginning their pubescent years.
BA~~68
Gerald had it right. It all depends on how you read the question.
ReplyDelete