A firm offers terms of 1/10, net 30. a) What effective annual interest rate does the firm earn when a customer does not take the discount? "b) What will happen to this effective rate if the discount is changed to 2 percent? " "c) What will happen to this effective rate if the credit period is increased to 45 days? " "d) What will happen to this effective rate if the discount period is increased to 15 days