Elaine goes out with a salesman who offers her a discount on a dress. He wants sex, but would prefer for her not to take advantage of the discount—he's dangling it in front of her as an incentive. She wants the discount, but would prefer not to have to sleep with him for it—she'd dangling it in front of him as an incentive. Both stall the other....and achieve a suboptimal social outcome. Kramer says "you need to establish trust before you can have a free exchange of sex...and discounts, the cornerstones of a healthy relationship."
The teacher poses to his students the Monty Hall problem, which investigates the probability of choosing a correct answer given three options and the subsequent probability of changing the original choice. The teacher explains why his students' instincts are not correct.
Charlie and Don try to make the three suspects talk using the prisoner's dilemma. They convince one to turn on the other two by giving all three a risk assessment of who is the one who has more to lose by going to prison.