Answer:
Karla's 15 miles per week to Brad's 17 miles per week.
Explanation:
First, we would need find the total number of miles each individual rides per week. We do this by dividing the total miles ridden by the number of weeks it took for each individual like so...
Karla: 135 / 9 = 15 miles per week
Brad: 102 / 6 = 17 miles per week
Finally, the comparison would be
Karla's 15 miles per week to Brad's 17 miles per week.