Answer:
62 miles/hour
Explanation:
You can solve this the way you would solve any other "averaging" problem.
(50 + 50 + 70 + 70 + 70) / 5 = 62
He traveled 50 mi/hr for the first 2 hours and 70 mi/hr for the remaining (3 hours). Add up all the values and divide by the amount of hours (5).