A large retailer obtains merchandse under the credit terms of 1/15, net 40 , but routinely takes 50 doys to pay its biks. (Because the retailer is an important cuistomec, suppliers allow the nim to stretch its credit terms.) What is the retaller's effective cost of trade credit? Assume a 305 -day year, Do not round intermediete caiculatons. Round your answer to two decimal piaces