The kilometers Gabriel drove is 120 km .
The first step is to determine Gabriel's average speed. Average speed is the total distance travelled per time.
Average speed = total distance / total time
80 / 1 = 80 km/hr
The formula to be used to determine the kilometers driven is:
Average speed x total time
80 x 1.5 = 120 km
To learn more about average speed, please check: brainly.com/question/9834403?referrer=searchResults