16. The night before an economics exam, you decide to go to the movies instead of staying at home studying. Once you take the exam, you obtain a grade of 70 instead of the usual grade of 75. Calculate the opportunity cost of going to the movies.

C.O. = _______.

24. With the savings from your job you opened a small laundry. The following table summarizes the data of the work performed by the two workers hired in the first month. Calculate Mary's opportunity cost if she does laundry.

Worker	Laundry	Ironing
Mary	20 pieces	25 pieces

C.O. = _______.

25. With the savings from your job you opened a small laundromat. The following table summarizes the data of the work performed by the two workers hired in the first month. Calculate Joseph's opportunity cost if he is a laundry worker.

Worker	Laundry	Ironing
Joseph	10 pieces	15 pieces

C.O. = _______.

26. With the savings from your job you opened a small laundry. The tables above summarize the data on the work performed by the two workers hired in the first month. Calculate Joseph's opportunity cost if he works as an ironer.

C.O. = _______.