To find the unit rate of minutes per mile, you can divide the total number of minutes by the total number of miles.
Oscar runs 7 miles in 84 minutes.
To find the minutes per mile:
\[ \text{Minutes per mile} = \frac{\text{Total minutes}}{\text{Total miles}} = \frac{84 \text{ minutes}}{7 \text{ miles}} = 12 \text{ minutes per mile} \]
So, the unit rate is 12 minutes per mile.