A car accessory is sold for $50.85. The store's markup based on cost is 39%. (a) What is the cost of the car accessory? (b) What is the rate of markup based on selling price? (a) The cost of the car accessory is $. (Round the final answer to the nearest cent as needed. Round all intermediate values to six decimal places as needed.) (b) The rate of markup based on selling price is %. (Round the final answer to two decimal places as needed. Round all intermediate values to six decimal places as needed.)