St. Joe Trucking has sold an issue of $6 cumulative preferred stock to the public a price of $60 per share. After issuance costs, St. Joe netted $57 per share. The Company has a marginal tax rate of 40 percent. a. Calculate the after-tax cost of this preferred stock offering assuming that this stock is a perpetuity. b. If the stock is callable in 5 years at $66 per share and investors expect it to be called at that time, what is the after-tax cost of this preferred stock offering? (Compute to the nearest whole percent.)