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 :
$A \cup A^{\prime}=\ldots$
Let $\mathrm{U}$ be universal set of all the students of Class $\mathrm{XI}$ of a coeducational school and $\mathrm{A}$ be the set of all girls in Class $\mathrm{XI}$. Find $\mathrm{A}'.$
Taking the set of natural numbers as the universal set, write down the complements of the following sets:
$\{ x:x\, \ge \,7\} $
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
$(B-C)^{\prime}$