please help with this problem. please use Excel and show all calculations and formulas. thank you.

Calculate the nominal annual cost of nonfree trade credit under each of the following terms. Assume that payment is made either on the discount date or on the due date. a. 2/15, net 35 b. 1/10, net 30 c. 2.5/15, net 45 d. 3/10, net 50 e. 2/15, net 40