Answer:
Either 40 or 80, depending on whether you worded the question correctly or not.
Explanation:
If you mean he has gone 80 miles:
velocity is distance per time, so 80miles/2hours = 40 miles/hour
If you mean he is going 80mph, then the answer is in the question, 80 miles/hour and the distance he has traveled is in miles, therefore you need to multiply by hours, i.e., 80*2=160 miles.