In this humorous example showcasing the gap between the "real world" and theory, Thornton Melon challenges the assumptions that Dr. Barbay poses to the class about starting a new company. Thornton asks questions such as why they are building a factory instead of leasing one and what product they're selling. Dr. Barbay is not amused by his interjections.
Kramer and Newman hatch a scheme to arbitrage bottles from NY, where the deposit is 5 cents, to Michigan, where the deposit is 10 cents. They can't figure out how to make the costs work; gas is too expensive (variable costs), and there's too much overhead (fixed costs of tolls, permits, etc.) with using a semi to haul the bottles in volume. Finally, they hatch a scheme to use a mail truck, which lowers their variable and fixed costs to zero.
A question is posed to Ben Campbell by Professor Micky Rosa. Without hesitation Ben answers this correctly, which convinces Professor Rosa that Ben would be a good addition to their "card counting team."