Instead of asking for an answer to something as simple as this, you need to learn how to reason things out and figure it out for yourself. You probably don't even know what "mph" really means. Once you know what this means then you can figure out any problem like this. You can begin by asking youself if you travel 20 miles in 60 minutes, what is your mph?... once you get the idea of what this means then you can work out any such similar propblem, but if you just ask someone else for the answer you are going to be in deep doo-doo if you need to know something like this and there is no one around to ask.
The larger proble is that if individuals can't learn how to figure things out for themselves then eventually they become helpless and dependent on others for everything.
