For any two sets A and B,
Question:
For any two sets $A$ and $B, A \cap(A \cup B)=$
(a) A
(b) B
(c) ϕ
(d) none of these.
Solution:
(a) A
$A \cap(A \cup B)=(A \cap A) \cup(A \cap B)=A \cup(A \cap B)=A$