Present value long dash Mixed streams

Consider the mixed streams of cash flows shown in the following table,

a. Find the present value of each stream using a 4% discount rate.

b. Compare the calculated present values and discuss them in light of the undiscounted cash flows totaling $20000 in each case. Is there some discount rate at which the present values of the two streams would be equal?

Year Cash flow stream B $- 15,000 $5,000 $12,500 $7,500 $10,000 $10,000 $7,500 $12,500 $5,000 $- 15,000 $20,000 $20,000 Totals