Make correct statements by filling in the symbols $\subset$ or $ \not\subset $ in the blank spaces:

$\{ x:x$ is a student of class $\mathrm{XI}$ of your school $\}  \ldots \{ x:x$ student of your school $\} $

Decide, among the following sets, which sets are subsets of one and another:

$A = \{ x:x \in R$ and $x$ satisfy ${x^2} – 8x + 12 = 0 \} ,$

$B=\{2,4,6\}, C=\{2,4,6,8 \ldots\}, D=\{6\}$

The smallest set $A$ such that $A  \cup  \{1, 2\} = \{1, 2, 3, 5, 9\}$ is

State which of the following sets are finite or infinite :

$\{ x:x \in N$ and $2x – 1 = 0\} $

Let $A=\{a, e, i, o, u\}$ and $B=\{a, b, c, d\} .$ Is $A$ a subset of $B ?$ No. (Why?). Is $B$ a subset of $A ?$ No. (Why?)