Find the union of each of the following pairs of sets :

$A=\{a, e, i, o, u\} B=\{a, b, c\}$

If $A=\{1,2,3,4\}, B=\{3,4,5,6\}, C=\{5,6,7,8\}$ and $D=\{7,8,9,10\} ;$ find

$A \cup C$

If $A=\{3,5,7,9,11\}, B=\{7,9,11,13\}, C=\{11,13,15\}$ and $D=\{15,17\} ;$ find

$A \cap \left( {B \cup C} \right)$

Find the intersection of each pair of sets :

$X=\{1,3,5\} Y=\{1,2,3\}$

Using that for any sets $\mathrm{A}$ and $\mathrm{B},$

$A \cap(A \cup B)=A$

In a school, there are three types of games to be played. Some of the students play two types of games, but none play all the three games. Which Venn diagrams can justify the above statement ?