Answer: 7.
- A 7
- B 8
- C 6
- D 5
Correct answer: A. 7
Explanation: A proper subset excludes the set itself, so the count is 2³ − 1 = 7.
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