Question

if $X^{\prime }=Y$ then ${(X\cap Y)}^{\prime }$ is equal to

• A. $\varphi$
• B. $X$
• C. $U$
• D. $Y$

Answer 1

Answer: (C)

$U$

Given

$X^{\prime }=Y$

$X$ $\cap$ $Y=X$ $\cap$ $X^{\prime }$

$(X$ $\cup$ $X^{\prime }{)}^{\prime }$ $=U$(Universal set)

Complement of null set is Universal set $U$.