In order to figure this out, let's get the total number of plates that Lori got. 5 + 10 is 15. Lori has a total of 15 plates. Since we would want to know what percent of her plate collection is blue, we then divide 5 by 15. 5/15 is equal to 0.33333. This is equivalent to 33.33%. 33.33% of Lori's plates are blue.