The pharmacists milkweed concoction didn’t work. It only gave the queen split ends. However, the queen, in a rare kind hearted moment, agreed to let the pharmacist try again. This time he has decided to combine a mixture 50% sorghum with a mixture containing 75% sorghum to create a 10 ounce mixture containing 60% sorghum. How many ounces of the 50% mixture should the pharmacist use?