At the same time Kris leaves Washington, D.C. For Detroit, Amy leaves Detroit for Washington, D.C. The distance between the cities is 510 miles. Amy's speed is 5 mph faster than Kris. How fast is Kris driving if they pass each other in 6 hours?

The answer I came up with is 80 mph, not sure if I did this correctly, please help

Um... no, I am getting something else. (I might be wrong though, it's very late here right now :p)

Could you show us your work so that we know where you might have got wrong? :)