Calculate percentages to the nearest 0.1% a. Merchant A operates on a rate of markup on cost of 45%. If she later marks the price of a few items down to their cost in order to attract additional customers to the store, what rate of markdown can she advertise? (Round your answer to one decimal place.) Rate % b. Merchant B operates on a 45% rate of markup on selling price. If he later marks the price of a few items down to their cost in order to attract additional customers to the store, what rate of markdown can he advertise? (Round your answer to one decimal place.) Rate %