MST LTDA sells goods in 4 bimonthly payments of R$ 160,000.00 each. As an alternative, this same merchandise can be sold as follows: 30% of its value as a down payment and the remainder at the end of 6 months (one semester). Since the rate charged in the business is 30% per year, compounded quarterly, it is necessary to calculate:

a) the value of the single installment due at the end of the sixth month after being sold.

b) the monthly inflation rate knowing that the real gain was 1.8% per month