La probabilità è un'intuizione (solitamente sbagliata)

Dal Mitzenmacher:

Exercise 1.6: Consider the following balls-and-bin game. We start with one black balland one white ball in a bin. We repeatedly do the following: choose one ball from thebin uniformly at random, and then put the ball back in the bin with another ball of thesame color. We repeat until there are n balls in the bin. Show that the number of whiteballs is equally likely to be any number between 1 and n-1.

Facile coi conti, molto meno con la fantasia.