Present value of annual net cash flow:
Using the 20% column:
14,000 x 0.833 = 11,662
12,000 x 0.694 = 8,328
10,000 x 0.579 = 5,790
8,000 x 0.482 = 3,856
18,000 x 0.402 = 7,236
Add the following, you will get the total of 36,872 this is the net present value.