10 mph
The pace to run a half mile in 4 minutes 13 seconds is 7.12 (7.11462451) miles per hour.
You would have to keep an average pace of about 12mph (that is, miles per hour) to finish the mile in 5 minutes
To run 1600 meters at a pace of 10 and a half minutes per mile requires 10 minutes 26.4 seconds.
This is a pace of 4.91 minutes per mile.
8.06 minutes per mile.
The time it takes to run 15 miles depends on your running pace. For example, if you run at a pace of 10 minutes per mile, it would take you approximately 150 minutes, or 2.5 hours. At a faster pace of 8 minutes per mile, it would take about 120 minutes, or 2 hours. Your individual fitness level and running speed will ultimately determine the duration.
Maintain a pace of 7 mph.
12 mph. If you ran 1 mile in 5 minutes, and kept that pace, you would run 12 miles in 60 minutes (1 hour).
(31 miles) x (10 minutes/mile) = 310 minutes = 5hours 10minutes
60 (minutes/hour) / 9.5 (minutes/ mile) = 6.316 miles per hour
It would take 3 minutes 6 seconds at that pace.
She can run 18.75 miles in 15 minutes at that pace. This, however, is humanly impossible since she would have to run at 75 mph!