If $n ( A ) = 5 , n ( B ) = 11$ and $n ( A \cap B ) = 3$, what do you know about $n ( A \cup B )$ ?
A) $n ( A \cup B ) = 12$
B) $n ( A \cup B ) = 16$
C) $n ( A \cup B ) = 14$
D) $n ( A \cup B ) = 13$

Question

Quizplus · Accepted Answer

The formula for the union of two sets is $n ( A \cup B ) = n ( A ) + n ( B ) - n ( A \cap B )$. Substituting the given values, $n ( A \cup B ) = 5 + 11 - 3 = 13$.

If n(A)=5,n(B)=11n ( A ) = 5 , n ( B ) = 11n(A)=5,n(B)=11

If $n ( A ) = 5 , n ( B ) = 11$