Annual credit sales of Nadak Co. total $331.4 million. The firm gives a 2.25% cash discount for payment within 10 days of the invoice date; 80% of Nadak's accounts receivable are paid within the discount period.

a. What is the total amount of cash discounts allowed in a year? (Enter your answer in millions rounded to 2 decimal places.)

b. Calculate the approximate annual rate of return on investment that Nadak Co.s cash discount terms represent to customers who take the discount. (Assume a credit period of 30 days and 360-days year). (Round intermediate calculations to 2 decimal places. Enter your answer as a percentage rounded to 1 decimal place (i.e., 32.1).)