A class has two students, who face a final exam worth 100% of their final grade. Final grades are determined according to relative performance on the final exam, and each student's final exam score depends upon whether or not she studies. If both students study, each will get a B- for the course. Likewise, if neither student studies, each gets B- for the course. If one student studies and the other does not, the student who studied will get an A, while the student who did not study will get a D. A student's payoff is based on both her grade and whether she studied. If a student did not study, she gets a payoff of 15 from an A, 7 from a B-, and 5 from a D. If she studied, then subtracted from those numbers is the cost of studying. Each student can have either a high cost of studying (3), or a low cost of studying (1). For example, suppose both students study, and that student 1 is high cost while student 2 is low cost. Then student 1 earns a payoff of 7 - 3 = 4, while student 2 earns a payoff of 7