A roulette wheel in las vegas has 38 possible outcomes of those 38 outcomes, 18 are red, 18 are black, and 2 are green suppose you bet 2 dollars on the outcome being red now, assume that the casino will return your investment and give you an additional 2 dollars if you win, but will keep your 2 dollars if you lose how much money should you expect to win each game (now you know why casinos are making so much money)