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.
No. Let $A=\{1\}, B=\{\{1\}, 2\}$ and $C=\{\{1\}, 2,3\} .$ Here $A \in B$ as $A=\{1\}$ and $B \subset C$. But $A \not\subset C$ as $1 \in A$ and $1 \notin C$
Note that an element of a set can never be a subset of itself.
Which of the following pairs of sets are equal ? Justify your answer.
$\mathrm{X} ,$ the set of letters in $“\mathrm{ALLOY}"$ and $\mathrm{B} ,$ the set of letters in $“\mathrm{LOYAL}”.$
State whether each of the following set is finite or infinite :
The set of circles passing through the origin $(0,0)$
Let $A=\{1,2,3,4,5,6\} .$ Insert the appropriate symbol $\in$ or $\notin$ in the blank spaces:
$ 0\, ........\, A $
Which of the following sets are finite or infinite.
The set of prime numbers less than $99$
Let $A=\{1,2,3,4,5,6\} .$ Insert the appropriate symbol $\in$ or $\notin$ in the blank spaces:
$ 2 \, ....... \, A $