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MCQ
The formula for the number of elements in A ∪ B is:
Unit-3 Sets and Relations
A n(A) + n(B) - n(A ∩ B)
B n(A) + n(B)
C n(A) + n(B) + n(A ∩ B)
D n(A) - n(B)
Explanation

Adding n(A) and n(B) counts the common elements twice, so n(A ∩ B) must be subtracted.

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