To find Rachel’s unit walking rate in both miles per hour and hours per mile, we can follow these steps:

1. Miles per Hour (mph): The unit rate in miles per hour (mph) is calculated by dividing the number of miles Rachel walked by the number of hours it took her.

   Formula: $\text{Miles per hour} = \frac{\text{miles walked}}{\text{hours taken}}$

2. Hours per Mile: The unit rate in hours per mile is calculated by dividing the number of hours by the number of miles Rachel walked.

   Formula: $\text{Hours per mile} = \frac{\text{hours taken}}{\text{miles walked}}$

If you can provide the number of miles she walked and the hours it took, I can compute the exact values for both rates.

Do you have any other details to provide?