Unit rate feet per second 180 miles over 2 hours

So that is equal to 180 miles per 2 hours which is 90 miles per hour if each hour has the same m/hr rate.
You can set up a proportion:
let x = number of miles per hour

cross multiply and you get
2x=180
divide both sides by 2 and you get
x=90
so you get the same answer both ways,
90 miles per hour