Since it’s takes 4 hours in 240 minutes you have to divide those numbers to get miles per hour. The answer is simple. Just imagine it’s like 24 divided by 4. What is it? It’s 6. But since it’s 240 not 24 it would be 60. So that means it’s 60 miles per hour. So divide 90 by 60 and get 1.5 or 1 and a half miles in fraction form. So it’s D.
Hope this helps!
