8. (5 points) Person A and Person B stand facing each other 30 meters apart. They play "Rock-Paper-Scissors," with the winner moving forward 8 meters, the loser moving back 5 meters, and in the case of a tie, both moving forward 1 meter. After 10 rounds, they are 7 meters apart. How many rounds did they tie?
【Answer】Solution: Assume all games end in a draw, then the distance between the two people should be: $30-10 \times 2=10$ (meters), $(10-7) \div(8-5-2)=3$ times (win)

Draws are: $10-3=7$ (times),
Answer: The number of draws is 7.
Therefore, the answer is: 7.