Depends on ur speed. Bikes go between pedestrian speed (your granny) and 70 miles/hour (maximum downhill speed on the famous "tour de france" bike race).
On a flat road with a moderately practiced biker, I'd say that 10 to 15 mph should be possible.
I have biked to work for half a year. It was about 6 miles away but in the river Rhine valley while I live up the hills. Took me half an hour to get there and one hour and a half to go back home in the evening.
I do 10km (or more) everyday, which is 6.2 miles, my best time is just on 19 minutes but I average at about 21-22 minutes. I think the average for an average person is about 25 minutes. It depends on the terrain and weather too. I cycle indoors on an exercise bike, but if you were outside, having to slow down for corners, stop at roads etc it could be more.
It takes nearly 30mts.....
Less than an hour depending on hills and how fast you pedal.
I think it depends on how fast you're pedaling :)
About half an hour at a moderate pace.
Like 1 hr or less