Using proportions, it is found that the speed of the runners are of 16 mph and of 20 mph.
<h3>What is a proportion?</h3>A proportion is a fraction of a total amount.
After 30 minutes, the runners are 2 miles apart, hence the second runner is 4 miles per hour faster than the second, that is:
.
The first runner's speed is 4/5 of the speed of the second runner, hence:
Hence, the speed of the runners are of 16 mph and of 20 mph.
More can be learned about proportions at brainly.com/question/24863377