20.6 miles per hour.
It depends on how fast your actually going.
If you rode 12 miles in 38 minutes, then it took you 3.1666 minutes to ride 1 mile (38/12). So, if you divide 60 by the time it took you to ride one mile it gives you the mph 60/3.1666 = 18.95mph.
11/2 miles in 15 minutes = 6 mph
This is completely dependent on how fast you travel. Speed is distance/time.
542 miles in 12 hours and 37 minutes equates to an average speed of 42.96 miles per hour.
You are averaging 12 miles per hour.
If an aircraft travels 120 miles in 12 minutes how fast is the aircraft going? The aircraft travels 120 miles in 12 minutes, which is 1/5 of an hour. Therefore, in 55 (one) hour, it would travel 5 × 120, or 600 miles. The aircraft is traveling 600 miles per hour.
250 mph
A marathon runner certainly can; that is 1 mile in 7.5 minutes. That is a bit fast for the average person, however, to keep up that pace for 12 miles
20 minutes.
55 minutes = 11/12 hours. 19 miles per 11/12 hours = 20.7272 mph or 20+1/8 mph
20/12=1 2/3 hours. Or 1 hour, 40 minutes.