Since there are 1000 milliliters in a liter, that means that there are 33.8/1000 fluid ouncers per milliliter. That means that each 200 mil bottle is 6.76 fluid ounces or 33.8/1000*200. 45/6.76 = 6.66 but you have to round up to a whole number of bottles since you can buy 2/3 of a bottle which makes your answer 7 bottles.