Question 1133365
second car's speed=x mph
first car's speed=2x mph
The difference in speed is x mph (2x-x)
In 3 hours, they are 90 miles apart, so the difference is 90 mi/3h or 30 mph
The difference is also the second car's speed, x, or 30 mph ANSWER
The first car is traveling 60 mph, twice as fast.  In 3 hours, they are 90 miles apart