Let $U=\{1,2,3,4,5,6,7,8,9\}, A=\{1,2,3,4\}, B=\{2,4,6,8\}$ and $C=\{3,4,5,6\} .$ Find
$A^{\prime}$
Fill in the blanks to make each of the following a true statement :
$A \cap A^{\prime}=\ldots$
Taking the set of natural numbers as the universal set, write down the complements of the following sets:
$\{x: x+5=8\}$
Fill in the blanks to make each of the following a true statement :
$\varnothing^ {\prime}\cap A$
Fill in the blanks to make each of the following a true statement :
$A \cup A^{\prime}=\ldots$