Use the following data to answer the followingquestions: Untied States can produce either 18 oranges or 9 apples in an hour, whereas, Mexico can produce either 16 oranges or 4 apples in an hour.

1. What are the opportunity costs of producing 1 apple for United States and Mexico respectively?
2. What are the terms of trade between apples and oranges that would allow both Untied States and Mexico to gain by specialization and exchange?