Devin and Juan took turns driving to Integer Park. Devin drove 3 out of every 5 miles. By the time they reached Integer Park, Juan had driven 5 fewer miles than Devin. How many miles did Devin drive?
Devin drives 3 x
Juan drives 2 x
2 x + 5 = 3 x
x =5
so 3 x = 15