For this case, what we must do is calculate the speed of the runner.
We have then that the speed is given by:

Where,
d: distance
t: time
Substituting values we have:


Answer:
the runners unit rate is:

Answer:
18 
Step-by-step explanation:
0 it has no simplest form
Answer:
Refraction is what happens when light passes through some medium and changes it's direction because of it. For instance, when light travels through a lens light is bent as it goes from air to glass and back to air again. :)