State which of the following sets are finite or infinite :
$\{ x:x \in N$ and $x$ is odd $\} $
Since there are infinite number of odd numbers, hence, the given set is infinite.
The number of non-empty subsets of the set $\{1, 2, 3, 4\}$ is
State whether each of the following set is finite or infinite :
The set of letters in the English alphabet
Which of the following are sets ? Justify your answer.
A collection of most dangerous animals of the world.
Are the following pair of sets equal ? Give reasons.
$A = \{ x:x$ is a letter in the word ${\rm{FOLLOW }}\} $
$B = \{ y:y$ is a letter in the word $WOLF\} $
Let $A=\{1,2,\{3,4\}, 5\} .$ Which of the following statements are incorrect and why ?
$\{ \{ 3,4\} \} \subset A$
