Say a single-number bet has a 35:1 payout, and you betR$1. If you win, you'll get your money back plusR$35. Another example: If you win aR$100 bet (for a 35:1 payout), you get a total of $3,600 ($3,500 profit plus theR$100 you initially bet).
While it is theoretically possible to make a living off of playing roulette, it is extremely difficult and highly unlikely. Roulette is a game of chance, and the house always has an edge, which means that over time, the odds are in favor of the casino.