Return required to induce investor to buy two-year security

Question

Problem: The following pattern for one-year Treasury bills is expected over the next four years:

Year1, 3%
Year2, 5%
Year3, 6%
Year4, 7%

Q1. What return would be necessary to induce an investor to buy a two-year security?

Q2. What return would be necessary to induce an investor to buy a three-year security?

Q3. What return would be necessary to induce an investor to buy a four-year security?