It doesn't matter how long you run for, only that you want to run at one speed, a six minute mile. In other words, your six minute mile is that speed in your first through fifth, and every minute after that. The math... a six minute mile is one mile per six minutes which equals 10 miles for every sixty minutes, or ten miles per hour.
Your average speed must be at least 10 mph
You're thinking of the four minute mile. Many can run six minute miles.
in terms of speed, 10 mph. in terms of 400 splits, 1:30 for each 400.
That's a ten-minute mile, or six miles per hour.
it's pretty good. that means you can run a mile in six minutes consistently.
It takes me 10 minutes but I'm training for a race so I'm used to running.
it depends on how fast you run...
That's a rather complicated question and has more to do with your conditioning than anything. If you do not run (or work out, swim, etc) other than whenever you run the mile, it can be upwards of the ten minute range. Medium amounts of running (by yourself a mile or three a couple times a week) or other physical exercise (though this might not be as effective) should work you into about the 7-8 or so minute range. Working out with others (which helps) five times a week, varying workout, etc.-which is easier if you are running on a cross-country or track team-might get you down to the six or even five minute range. But remember, some people are made so that they run fast. It is part of who they are. Some people need to work a lot to run very fast, and some are not built for running. What really matters is the effort that you put in. If you are working out, the mentality that you bring and the willingness to try and work at it. If you are just running the mile, the attitude that you are going to give it what you can is what really matters-times are different for everyone, but dedication is universal.
The average time for a mile is about 8 minutes, for runners its 6 minutes, so a sub six minute mile is good for a runner and a sub seven for nonrunners.