Google Interview Question - Probability

[RichardCranium]

Visualise the problem differently:

1. The first couple keep having babies until a boy is born.
2. Then the next couple start having babies until a boy is born to them.
3. Continue through the rest of the couples.

In this case, the couple gets replaced but the baby production just continues.

For each baby, the likelihood of it being boy/girl (50:50 or 52:48 or whatever) will not change.

So, the likelihood of boy / girl remains the same as it would if the couples continued having babies.

If all those couples' activities were then made concurrent, the ratio would still remain the same.


How's that for a solution & explanation?