Nope.
Let’s say the houses are 30 miles apart. At 30 mph, it took you an hour to make the trip. For the round trip to be at an average 60 mph, you would have to do the 60 miles round trip in an hour. But you already spent an hour on the first half, leaving you zero time left. You would need infinite speed.
In order to achieve an average velocity of 60 mph, starting with a 30 mph trip to the friends house 30 miles away, I would drive at 90 mph back to my house. Then I would keep going 30 miles past my house, turn around and return to my house at 90 mph. In total I have travelled for 2 hrs and covered a distance of 120 miles. My average velocity is 60 mph.
Yep, you guys are right. Tricky.