Fill in the blanks to make each of the following a true statement :
$\varnothing^ {\prime}\cap A$
If $A$ and $B$ be any two sets, then $(A \cap B)'$ is equal to
If $U =\{1,2,3,4,5,6,7,8,9\}, A =\{2,4,6,8\}$ and $B =\{2,3,5,7\} .$ Verify that
$(A \cup B)^{\prime}=A^{\prime} \cap B^{\prime}$
Taking the set of natural numbers as the universal set, write down the complements of the following sets:
$\{ x:x$ is an odd natural number $\} $
Fill in the blanks to make each of the following a true statement :
$A \cap A^{\prime}=\ldots$