Write the following sets in roster form :
$C = \{ x:x{\rm{ }}$ is a two-digit natural number such that sum of its digits is $8\} $
Examine whether the following statements are true or false :
$\{ 1,2,3\} \subset \{ 1,3,5\} $
Which of the following sets are finite or infinite.
$\{1,2,3, \ldots 99,100\}$
Decide, among the following sets, which sets are subsets of one and another:
$A = \{ x:x \in R$ and $x$ satisfy ${x^2} - 8x + 12 = 0 \} ,$
$B=\{2,4,6\}, C=\{2,4,6,8 \ldots\}, D=\{6\}$
In each of the following, determine whether the statement is true or false. If it is true, prove it. If it is false, give an example.
If $x \in A$ and $A \in B,$ then $x \in B$