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\} $
$C = \{ x:x{\rm{ }}$ is a two-digit natural number such that the sumof its digits is $8\} $
The elements of this set are $17,26,35,44,53,62,71$ and $80$ only.
Therefore, this set can be written in roster form as $C=\{17,26,35,44,53,62,71,80\}$
State whether each of the following set is finite or infinite :
The set of numbers which are multiple of $5$
Let $A=\{1,2,3,4,5,6\} .$ Insert the appropriate symbol $\in$ or $\notin$ in the blank spaces:
$ 4\, ......... \, A $
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 $A \not\subset B$, then $x \in B$
Which of the following are sets ? Justify your answer.
The collection of questions in this chapter.
Let $A, B$ and $C$ be three sets. If $A \in B$ and $B \subset C$, is it true that $A$ $\subset$ $C$ ?. If not, give an example.