Depends on how fast they are
a person in the Olympics of 2008 should be able to run the mile in about 3:50 or less to be competitive
A 23-year old man should be able to run a mile is about 8 minutes. Most people should be able to walk a mile in about 20 minutes.
8 minutes at least
If your goal is a 11 min. mile and a half, your mile time should be about 7:33.
1 mile in 20 minutes
a mile should be ran in 7 minutes or so. if you're in pretty good shape.
the fastest mile is a 0.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001
About fiftee minutes, though you should be able to do it quicker if you're fast.
I would think that is a reasonable start. Fast walking should produce a mile in 15 minutes. The nine minutes should be able to be improved on though.