hey the professor gave us a few practice questions for an upcoming quiz, I could use some help..

1)Conceptually, what is the difference between the methods used to estimate the expected future profits and the expected future cash flows of a potential investment opportunity?

2)Why is the reinvestment assumption associated with the NPV calculation more appropriate than the reinvestment assumption associated with the IRR calculation?

3) Tamir works for a firm that owns and operates five car dealerships.The chief investment officer suggests that the firm should buy gold as an investment because he read in the paper that the demand for gold is expected to go up significantly in the future.Should Tamir expect this to be a value enhancing investment?