Problem
In each of the following cases, determine the opportunity cost of each worker.
I. In 30 minutes, Deepika can either make miso soup or she can clean the kitchen. In 15 minutes, Yanjun can make miso soup; it takes Yanjun an hour to clean the kitchen.
II. In one hour, Ma can bake 20 cookies or lay the drywall for two rooms. In one hour, Kareena can bake 100 cookies or lay the drywall for three rooms.
III. Kejiao can build two glass sculptures per day or she can design two full-page newspaper advertisements per day. Anushka can build one glass sculpture per day or design four full-page newspaper ads per day.
IV. In the Khan family, Shah Rukh can write 12 excellent poems per day or solve 100 difficult physics problems per day. Saif Ali can write one excellent poem per day or solve 0.5 difficult physics problems per day.