At 900 AM two trains are 715 miles apart traveling toward ea

At 9:00 AM, two trains are 715 miles apart traveling toward each other on parallel tracks. If one train is traveling at a rate that is ten miles per hour faster than the other train and they meet after 5.5 hours, how fast is each train traveling?

Solution

let x=rate of slower train
x+10=rate of faster train
travel time=distance/speed
x+(x+10)=rate at which trains are approaching each other
..
715/2x+10=5.5
5.5(2x+10)=715
11x+55=715
11x=660
x=60
x+10=70
rate of slower train=60 mph
rate of faster train=70 mph