You are considering a safe investment opportunity that requires a $780 investment today, and will pay $570 two years from now and another $580 five years from now. 

a. What is the IRR of this investment? 

b. If you are choosing between this investment and putting your money in a safe bank account that pays an EAR of 5% per year for any horizon, can you make the decision by simply comparing this EAR with the IRR of the investment? Explain.