A probability problem by cool dude
Teanchi and Beanchi are a married couple (don't ask me who he is and who she is). They have two kids, one of them is a girl. Assume safely that the probability of each gender is . What is the probability that the other kid is also a girl?
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1 solution
This is a famous question in understanding conditional probability, which simply means that given some information you might be able to get a better estimate.
The following are possible combinations of two children that form a sample space in any earthly family: Girl - Girl, Girl - Boy, Boy - Girl, Boy - Boy,
Since we know one of the children is a girl, we will drop the Boy-Boy possibility from the sample space. This leaves only three possibilities, one of which is two girls. Hence the probability is 1/3