According to Running Free, the average time to compete a 5K (3.1 miles) event is 28 minutes and 48 seconds. In January 2014, Flotrack reported a new world record for running 5K indoors in only 13 minutes, 1 second.
An Associated Press article posted on Active Network reports the women's world record time for an outdoors 5K is 14 minutes, 54 seconds.
Nanci Hellmich, writing for USA Today, reports that a moderate-to-brisk walking pace is around 3 miles per hour, indicating that walking 3 miles should take around an hour. Therefore running a 5K (approximately 3 miles) should take somewhere between 13 and 60 minutes.