Depending on how fast you can walk in an hour, perhaps two or three.
According to Wikipedia, "World-class racewalkers (male and female) can average under seven and eight minutes per mile (or under four and five minutes per kilometre, respectively)..."
You buy one of those things that track how many steps you walked. Walk for an hour and you got your answer
4.70 km walked in 50 minutes equates to 3.5 miles per hour.
It depends on how fast you walk. If you walk 3 miles/hr for 1 hour you will have walked 3 miles. If you walk at 5 miles/hr for 1 hour you will have walked 5 miles... etc.
This is somehow a strange question, but I'll try to answer it. You walked 12 miles, vice versa, it's 12miles per hour.
0
You walked 2.083 miles in 50 minutes.
If you ran 3 miles in a half an hour you were averaging six miles an hour.
About 11.2 miles.
(2.5) ( pi/sqrt(pi2) ) sin(pi/2) miles per hour
60 miles
70 miles
75 miles per hour.