We can figure out how long Michael's trip took by realizing that 30 mph is 3 times 10 mph. Because of this, the trip home will take 1/3 the amount of time it took to go up the hill. This makes the equation 24 + 8 = 32 minutes for the whole trip.
Now we need to figure out how long the trip was. We can do this by multiplying 10 minutes by 24/60, which equals 4. This means that Michael went 4 miles there, and 4 miles back. So Michael went a total of 8 miles.
Now we know that Michael went 8 miles in 32 minutes. Now, we multiply 8 by 60/32. This gives us 15, so Michael went 15 miles per hour on average in the trip.
People moved to the cities to escape war. Some people had left the countryside to work in the arms industry and some had left for Rome looking for subsistence. Rome became the most populous city in Europe and West Asia.
