Every day after class, Mr. Dabble’s third grade class must clean the room. Somekids sweep and some kids put things away. Everyone thinks that sweeping ismore fun, and so he lets the best-behaved kids sweep. Is the classroom likelybeing cleaned as fast as possible? Why or why not?

Finish the sentence: “When someone can spend their time on X or on Y, theopportunity cost of X is . . .”

In the shared production possibility frontier depicted in the following illlustration, who has the comparative advantage in brick? How do you know?

B. There are three brothers—Justin, Travis, and Griffin. Each of them can write8 ghost stories in an hour. Or, they can spend their time grooming horses. Justin’sopportunity cost of grooming a horse is 1/2 a ghost story. Travis’s opportunitycost is 1 ghost story. Griffin’s opportunity cost is 2 ghost stories. If each of themhas an hour of time available, draw each of their individual production possibility frontiers, as well as their shared PPF.
C. Armond and Alvin currently do not specialize and trade. Every day, each of themmakes 10 shirts and 20 pairs of pants. Then, they decide to specialize and tradewith each other. But they find no gains from trade! Together they make 20 shirtsand 40 pairs of pants. What must be true about Armond and Alvin?
D. Why are country-level PPFs typically drawn as curves but individual-level PPFs are drawn as straight lines?
E. The country of Khartem produces chairs and tables. Globally, they happen tohave a comparative advantage in tables, and export tables around the world.
Then, there’s a boom in interest in tables globally. It has suddenly become thefashion to replace your tables every year, and so demand for tables has gone wayup, and the price for tables has as well. How will Khartem’s PPF shift?
F. Spike spends his time baking cakes and solving puzzles. The following graphdescribes how much Spike can do in a day:

Which could explain a shift from PPFl to PPF2?
. Spike is too busy that day to produce anything.
. Spike rented a second oven that day.
. Spike lost his handy cake-icing knife.
. Spike has a headache that will make puzzles harder to solve.
G. Jared and Shane are great examples of the kind of people who benefit fromtrade. Jared is great at making jewelry but dislikes jewelry and loves shirts, whileShane is great at making shirts but dislikes shirts and loves jewelry. Write downJared and Shane’s production capacities such that, without trade, each of themconsumes 1 unit of the thing they don’t like and 1 of the thing they do like, andwith trade each of them consumes 1 unit of the thing they don’t like and 11 units of the thing they like. (Beware: this is a hard one!)