Puzzle

Let's assume you wish to have children—moreover, you want just as many girls as boys. In fact, you are so very much determined that you set out to not stop getting kids until the number of girls matches precisely the number of boys. How big a family will that make you, on average? read more »

Imagine you want to hire exactly one secretary. There is a fixed number, say, N persons available for this job and you may invite each of them for an interview. However, you have to tell each one right after the interview if you will hire her. Now, what is your strategy? read more »