Here’s something to stir your neurons.

You meet a woman who tells you that she has two children and that one of them is a boy. What is the probability that the other child is also a boy?

Assume that the children are not twins, that the sexes of children of the same parents are independent and that exactly 50 per cent of all children are boys.

Log your answer (anonymously if you like) as a comment.

### Like this:

Like Loading...

*Related*

## About aharmlessdrudge

Way back during the late Bronze age -- actually it was the 1950s -- all of us in high school had to take a vocational test to determine our interests and, supposedly, our future careers. I cannot remember the outcome, but I do recall one question that gave me pause. "If you were to win a Nobel prize, would it be in literature or in physics?" I hesitated over the question: although I enjoyed mathematics and science more than English class, I did have a couple of unfinished (and very bad) novels hidden away at home. I cannot remember what I chose back then, but the dilemma followed me to university, where I switched from mathematics to English and -- after a five-year stint in journalism -- back to mathematics. I recently retired as a professor of statistics. Retirement. What a good chance to revive my literary ambitions. I have finished a novel -- more about that in good time -- and a rubble of drafts of articles about mathematics and statistics is taking up space on my hard disk.