Average Speed Calculation

Question

An airplane leaves New York at 1:10 PM and arrives in Miami, 1125 miles away, at 3:40 PM. What is its average speed in miles per hour?

Isn't the formula speed = distance/time? It didn't work for me though, I got about 700 MPH.

Answer 1

I see my mistake. I did 1125/1.5, when it's supposed to be 2.5. A simple math error. The answer is 450.