Answer: 23 miles per hour
Another way to get a unit rate is the number of minutes it takes to travel 1 mile. 1 mile takes her about 2.61 minutes miles to drive.
Step-by-step explanation: Divide the number of miles by the time to get the unit rate in miles per hour.
138 ÷ 6 = 23 miles per hour.
If you divide the minutes by the distance, you get the unit rate in minutes per mile.
6 hours is 360 minutes. 60 minutes per hour is a unit rate.
138 ÷ 360 ≈ .3833 miles per minute
360 ÷ 138 ≈ 2.61 minutes per mile