If A∩B=∅A \cap B = \emptysetA∩B=∅, then which of the following is true?
n(A∪B)=n(A)+n(B)n(A \cup B) = n(A) + n(B)n(A∪B)=n(A)+n(B)
n(A∪B)=n(A)−n(B)n(A \cup B) = n(A) - n(B)n(A∪B)=n(A)−n(B)
n(A∪B)=n(A∩B)n(A \cup B) = n(A \cap B)n(A∪B)=n(A∩B)
A=BA = BA=B