Answer:
3.285714286
Step-by-step explanation:
Answer:
Option C.
Step-by-step explanation:
Solid in the given picture is a rectangular prism and a rectangular prism has 6 faces. Each face is formed by joining 4 vertices of the prism.
All the faces joining four vertices are: AFGB, BGHC, ADEF, DCHE, FEHG, ADCB.
From the given options,
Option (C). ADEF will be one of the face of the solid.
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