Question

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

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

Answer 1

Answer: (A)

$A\cup B$

$A\cap (X-B)=A-(A\cap B)$

$A\cap (X-B)\cup B=[A-(A\cap B]\cup B$

$=A\cup B$