Credit terms -- Find the effective annual rate of the following credit terms:

a. 2.1% discount if paid withing 6 days or net within 30 days (Round to two decimal places.)

b. 1.6% discount if paid within 35 days or net within 60 days (Round to two decimal places.)

c. 0.6% discount if paid within 13 days or net within 45 days (Round to two decimal places.)

d. 0.8% discount if paid within 23 days or net within 30 days (Round to two decimal places.)