Answer: 80.
- A 80
- B 90
- C 110
- D 30
Correct answer: A. 80
Explanation: n(A ∪ B) = 60 + 50 − 30 = 80.
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