Final answer:
The average speed of the athlete in the 100-meter race is 5 meters per second.
Step-by-step explanation:
The average speed of an athlete in a 100-meter race can be calculated by dividing the total distance traveled by the time taken to complete the race. In this case, the distance is 100 meters and the time taken is 20 seconds. To find the average speed, we divide 100 meters by 20 seconds, which equals 5 meters per second.