Brownsville, Texas, boasts being the southernmost international seaport and the largest city in the lower Rio Grande Valley. Ben Supple, an importer in Brownsville, has just received a shipment of Peruvian opals that he is pricing for sale. He paid $150 for the shipment. Assume he wants a 75% markup. Calculate the selling price when the markup is based on selling price. Selling price when the markup is based on selling price. Calculate the selling price when the markup is based on cost. Selling price when the markup is based on cost