If you bet 1€ on red, and the ball lands on red, you will win it back, and the amount is doubled, so you profit 1€. The black or green spaces equal 20, so the probability that the ball will not land on red is 20/37.
There are 18 red spaces 18, so the chance of a ball landing on a red is 18/37.Since there are 37 spaces, the probability of a ball landing on one of them is 1/37.These are the values that need to be calculated:
