Some clever mathematics teachers (redundant!) organzied a raffle for their school, selling tickets that cost $50 each. The advertised prize was an infinite number of dollars. They were beseiged by people wanting to buy tickets.
On the day of the drawing, it was announced that the lucky winner would get 1 dollar the first year, 1/2 dollar the next year, 1/3 dollar the next year, 1/4 dollar the next year,....