When you calculate the B/C ratio, you must convert the all future values to present value. a.) Why? Explain it briefly. b.) Please calculate the total of present value of the following cash flows of the project as follow: $ 50,000 in year 5, $ 40,000 in year 4, $ 30,000 in year 3, $ 20,000 in year 2 and $ 10,000 in year 1, and $5,000 in year 0; i = 10%