Answer:
28 are large or blue.
Explanation:
In this case they ask us how many are big or blue, that is, either of the two characteristics are valid, they tell us the following things in the statement:
17 large and blue, that is, 17 comply with what they ask us, since they are blue or large.
3 small and blue, that is 3 since they are blue, and we must take them into account.
8 large and red, you have to add 8 more because there are 8 large ones here.
12 small and red, none of them meet the requested characteristics, that is, they are in total:
17 + 3 + 8 = 28
28 are large or blue.