Question

If $A=\{1,3,5,7,9,11,13,15,17\}, B=\{2$, $4,6,8,10,12,14,16,18\}$ and $N$, the set of natural numbers is the universal set, then $A^{\prime} \cup\left[(A \cup B) \cap B^{\prime}\right]$ is

• A. $A$
• B. $A^{\prime}$
• C. $B$
• D. $N$.

Answer 1

Answer: (D)

$(A \cup B) \cap B^{\prime}=A \text { as } A \cap B=\phi$
$\Rightarrow A^{\prime} \cup\left[(A \cup B) \cap B^{\prime}\right]=A^{\prime} \cup A= N .$