A. Explain in detail a scenario in which calculated NPV is extremely sensitive to the discount rate used in the calculation, and conversely a scenario in which calculated NPV is not very sensitive to the discount rate used in the calculation. (i.e. if you were to graph NPV as a function of the interest rate used in the calculation, what would cause the line to be very steep, vs what would cause the line to be relatively flat).

B. Explain in detail how you can go about modifying the NPV calculation to appropriately compare projects of un-equal lives (hint, there are a few different acceptable answers here).