Answer:
300,000 mililiters
Explanation:
Remember that in international system the convertions are really easy because they are done 10 by 10, so from liters to mili, there are 3 spots, 1000, so there are 1000 mili-liters in a liter, so you just need to multiply the 300 liters of soda by 1000, which is 300,000 mililiters and that is what Justin sold at the baseball game in mililiters.