If you are running 6 miles per hour, then it takes you 10 minutes to run 1 mile. If you are running

If you are running 6 miles per hour, then it takes you 10 minutes to run 1 mile. If you are running 8 miles per hour, it takes you 7.5 minutes to run a mile. What does your speed have to be for your speed in miles per hour to be equal to your mile time in minutes?


From above, we have:

• 6mph x 10 minutes = 1 mile
• 8mph x 7.5 minutes = 1 mile

Notice that mph x minutes = 60 since there are 60 minutes in 1 hour?
So we have x mph x y minutes = 60.
Since we want mph and y (minutes) = x (mph), we have
x^2 = 60
x = sqrt(60)
x = 7.746 mph