194 Ten Principles of Economics
25. Tracy quits her job, which pays $25,000 a year, to finish her college degree. Her annual college
expenses are $12,000 for tuition and fees and $1,000 for books. What is her opportunity cost of
attending college for the year?
26. Melinda quits her job at a bank, which pays $30,000 a year, to enroll in a two-year graduate
program. Her annual school expenses are $22,000 for tuition and fees and $2,000 for books. What
is her opportunity cost of attending the two-year graduate program?
27. What does the term “marginal change” mean?