Answer:
1 change of tire
less
Step-by-step explanation:
Opportunity cost of the next best option forgone when one alternative is chosen over other alternative
Sue's opportunity cost of changing oil = number of tires she changes / number of oil she changes = 20 / 20 = 1 change of tire
Her opportunity cost of changing tires = 20 / 20 = 1
fred's opportunity cost of changing tires = 20 / 10 = 2
her opportunity cost of changing tires is less than that of freds