Answer:
5
Step-by-step explanation:
There are 5 faces on a square pyramid
Average speed = (distance covered) / (time to cover the distance)
= (500 miles) / (6.7 hours)
= (500 / 6.7) (mile/hour)
= 74.63 miles per hour.
I imagine there were quite a number of pit stops included in that.
This is faster than I expected when I first read your question.
That's really gettin' with it for cars in 1911 !