For each of the following financial situations, calculate the optimal cash discount percentage (each bullet is a separate answer, solve each bullet)

Cash discount period = 5 days, credit period = 75 days, and annual cost of capital = 15%

Cash discount period = 10 days, credit period = 30 days, and annual cost of capital = 12%

Cash discount period = 10 days, credit posted = 45 days, and annual cost of capital = 18%

Cash discount period = 10 days, credit period = 30 days, and annual cost of capital = 22%