How fast is each car traveling?

Question

Two cars start out together from the same place. They travel in opposite directions, with one of them traveling 5 miles per hour faster than the other. After five hours, they are 524 miles apart. How fast is each car traveling?

Answer 1

Car 1 travels distance D1 = 5 hours x (r miles/hr) = 5r miles

Car 2 travels distance D2 = 5 hours x (r + 5 miles/hr) = 5(r + 5) = 5r + 25 miles

 

Total distance apart is 524 miles, so 5r + 5r + 25 = 524, or 10r + 25 = 524.

 

10r = 499

r = 49.9 miles/hour for Car 1

 

r + 5 = 54.9 miles/hour for Car 2