Final answer:
Kim was faster on her way to the airport with an average speed of 60 miles per hour.
Step-by-step explanation:
To determine whether Kim's rate to the airport or from the airport was faster, we need to compare the average speeds for each trip. Average speed is calculated by dividing the total distance traveled by the total time taken.
Kim drove 120 miles in 2 hours to the airport. Therefore, her average speed to the airport is 120 miles / 2 hours = 60 miles per hour.
Kim drove 140 miles in 2.5 hours on her way back. Therefore, her average speed from the airport is 140 miles / 2.5 hours = 56 miles per hour.
Based on the average speeds, Kim was faster on her way to the airport with an average speed of 60 miles per hour.