It doesn’t necessarily have to be a professor if you think it would be appropriate for a university setting.
In highschool we had a maths teacher who always did the birthday paradox as a kind of opener in the first lesson. https://en.wikipedia.org/wiki/Birthday_problem
He bet 10€, that there are 2 students with the same birthday in the classroom of (abt) 30 students. The class was allowed to work out, if they want to accept the bet, or not (exchanging birthdates was not allowed ofc).
Usually the students think, that it’s nearly impossible, and accept the bet. Little did we know, that the probability of success was around 70% for the teacher.