Answer:
26
Explanation:
To find the minimum number of elements in the union of sets X and Y, we can consider the best-case scenario where there is maximum overlap between the two sets.
In the best-case scenario, if X and Y have some common elements, the minimum number of elements in X ∪ Y would be equal to the larger of the two sets.
Given n(X) = 26 and n(Y) = 13, the minimum number of elements in X ∪ Y would be max(n(X),n(Y) = max(26, 13) = 26.
So, the minimum number of elements in X ∪ Y is 26.