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

$\{a, b, c\} \ldots\{b, c, d\}$

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 $\} $

State which of the following sets are finite or infinite :

$\{ x:x \in N$ and $x$ is odd $\} $

Write the following sets in roster form :

$A = \{ x:x$ is an integer and $ - 3 < x < 7\} $

Write the following sets in roster form :

$B = \{ x:x$ is a natural number less than ${\rm{ }}6\} $

Show that the set of letters needed to spell $"\mathrm{CATARACT}"$ and the set of letters needed to spell $"\mathrm{TRACT}"$ are equal.