Answer:
4
9
Step-by-step explanation:
If X has 5 elements, and Y has 4 elements, and all 4 of Y's elements are the same as 4 of X's elements, then the intersection of the sets has 4 elements.
If X has 5 elements and Y has 4 elements, and they are all different, then the union of the sets has 9 elements.
Answer:
4
9
