A) What is the payback period (in annual terms) of the following cashflow stream?

Year 0: $-921.24

Year 2: $295.65

Year 8: $895.61

Year 10: $-238.36

Year 15: $949.73

Year 18: $-22.22

B) What is the IRR for the following cash flow stream? 

Year 0: $-3930 --- 

Year 2: $2839 --- 

Year 8: $2474 --- 

Year 12: $2668