posted by Jus .
An American style roulette wheel has individual compartments for the numbers 1 to 36, plus 0 and 00. If the payoff for a single-number bet is 35:1, what is the expected value of the winnings on any single-number bet?
Only if you win. The expected value (average return) is 35/38 of the bet.
I assumed that zero is not a bettable number (for the 35:1 payoff), so that there are only 36 possible winning numbers out of 38. The probability of a particular number from 1 to 36 is 1/38.