Răspuns :
A u K={1,3, 4, 5, 7}
A u B={3, 4, 5 , 6, 7, 8}
B u C={2, 4, 5, 6, 7, 8}
C u K={1, 2, 3, 4, 5, 7, 8}
A u B={3, 4, 5 , 6, 7, 8}
B u C={2, 4, 5, 6, 7, 8}
C u K={1, 2, 3, 4, 5, 7, 8}