The recently deceased Martin Gardner was known for, among other things, his mathematical puzzles. Here’s one of them.
I have two children, one of whom is a son born on a Tuesday. What is the probability that I have two boys?
The alleged answer may surprise you. Knowing the child’s gender and day of birth does actually affect the proability. Allegedly. The answer is hidden below.
(I’m not sure how this spoiler plugin is going to interact with the RSS feed, so just to be on the safe side I’m throwing a warning here that the answer is coming up and you should stop reading now if you don’t want it spoiled!) The chance of me having two boys is 13/27
I’ll also say that the answer is wrong , and in fact your initial intuition is right. (continue reading…)