It won fifteen of the thirty games in rainy days, so the winning rate in rainy days was 50%. This 50% winning rate is due to the previous 100 horse race, which won 20 races and lost 80 races. Of the 100 games, 30 were rainy and 70 were sunny. " The final probability after influencing the condition. So there is no need to consider other conditions. So in the end, the winning percentage is 50%.