Consider a 18-year-old high school graduate. If he goes to work, he can earn $30,000 per year. If he stays at school for another year and then goes to work, he can earn $31,000 per year. Assume the tuition for this year is $10,000, which needs to be paid upfront. The annual interest rate is 10%. What is his net present value of staying at school for another year and then going to work?