You have just joined an investment banking firm and you are offered two different salary arrangements. You can have $120,000 per year for the next three years, OR you can have $90,000 per year for the next three years, along with a $90,000 signing bonus today. The bonus is paid immediately, and the salary is paid at the end of each year. If the market interest rate is 5 percent, which do you prefer? (Needs numerical proof)