Set up the formula to calculate the net present value of the cash flows in questions 1 through 3, assuming a discount rate of 10% per year:
1) Receive $40 today and receive $40 one year from today.
2) Receive $40 today and receive $40 three years from today.
3) Pay $30 today, pay $40 one year from now, receive $40 two years from today, and receive $100 three years from today.