If $U=\{a, b, c, d, e, f, g, h\},$ find the complements of the following sets:

$B=\{d, e, f, g\}$

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 $\mathrm{A}'.$

Let $U=\{1,2,3,4,5,6\}, A=\{2,3\}$ and $B=\{3,4,5\}$

Find $A^{\prime}, B^{\prime}, A^{\prime} \cap B^{\prime}, A \cup B$ and hence show 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 a positive multiple of $3\} $

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

$(A \cup C)^{\prime}$

Fill in the blanks to make each of the following a true statement :

$\varnothing^ {\prime}\cap A$