Answer:
Sue's opportunity cost of changing oil is more than Fred's and her opportunity cost for changing tires is less than Fred's.
Explanation:
Opportunity Cost is the value of next best alternative sacrifised while choosing an alternative. Eg : If I can read English or Science & opportunity cost of reading it is reading Science.
Oil Tires Sacrifise Ratio (Oil:Tires)
Sue 20 20 20:20 = 1:1
Fred 20 10 20:10 = 2:1 or 1:0.5
Sue can change oil by sacrifising 1 unit tire, Fred can change oil by sacrifising 0.5 unit of tire. So, Sue's opportunity cost of changing oil is more than Fred's .
Fred can change tire by sacrifising 2 units of oil, Sue can change tire by sacrifising 1 unit of oil. So, Sue's opportunity cost of changing tires is less than Fred's.