Please show me how to solve this problem. I know the answer is 0.83 but how was this answer calculated?

Please show me how to solve this problem. I know the answer is 0.83 but how was this answer calculated? For a certain horse race comma the odds in favor of a certain horse finishing in second placehorse race, the odds in favor of a certain horse finishing in second place are given as 83 to 17. Express the indicated degree of likelihood as a probability value between 0 and 1 inclusive.