Question

If $A$ and $B$ are subsets of a set $X$ and $A$ and $B$ are disjoint sets, then what is $(A\cap (X-B\left)\right)\cup B$ equal to

• A. $A\cup B$
• B. $A\cap B$
• C. $A$
• D. $B$

Answer 1

The correct option is A $A\cup B$

From the given figure
$A\cap (X-B)$
$=A$ ...(i)
Therefore,,
$A\cap (X-B)\cup B$
$=A\cup B$ ...from(i).
Another possibility is $A$ and $B$ intersecting, in which you also get the same answer.