Answer: n(A∩B∩C).
- A n(A∩B∩C)
- B 0
- C n(A∪B∪C)
- D 1
Correct answer: A. n(A∩B∩C)
Explanation: The triple-overlap term n(A ∩ B ∩ C) is added back at the end.
A Venn diagram makes set identities visual: A∪B is everything inside either circle, A∩B is only the overlap, and the region outside both circles represents the complement of their union - directly illustrating De Morgan's law (A∪B)′ = A′∩B′.
Concept context
Types of sets, operations (union/intersection/complement), relations, and types of functions with domain and range