Final answer:
Susie ran 2/3 of a mile at a rate of speed of 13.33 miles per hour.
Step-by-step explanation:
Susie ran 2/3 of a mile in 1/20 of an hour. To find Susie's rate of speed, we divide the distance she ran by the time it took her to run that distance. The rate of speed is given by the formula rate = distance/time.
Calculating Susie's speed gives us:
Rate = (2/3 mile) / (1/20 hour) = (2/3) * (20/1) = 40/3 = 13.33 (repeating) miles per hour.
Therefore, Susie's running rate of speed was 13.33 miles per hour.