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\} $

Consider the sets

$\phi, A=\{1,3\}, B=\{1,5,9\}, C=\{1,3,5,7,9\}$

Insert the symbol $\subset$ or $ \not\subset $ between each of the following pair of sets:

$A, \ldots B$

In rule method the null set is represented by

Write the following sets in the set-builder form :

${\rm{\{ 5,25,125,625\} }}$

Set $A$ has $m$ elements and Set $B$ has $n$ elements. If the total number of subsets of $A$ is $112$ more than the total number of subsets of $B$, then the value of $m \times n$ is

Let $A=\{1,2,3,4,5,6\} .$ Insert the appropriate symbol $\in$ or $\notin$ in the blank spaces:

$ 0\, ........\, A $