Which of the following are sets ? Justify your answer.
The collection of all natural numbers less than $100 .$
Which of the following are examples of the null set
Set of even prime numbers
Let $A=\{1,2,\{3,4\}, 5\} .$ Which of the following statements are incorrect and why ?
$\{ 3,4\} \subset A$
Which of the following are sets ? Justify your answer.
A team of eleven best-cricket batsmen of the world.
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 $“\mathrm{LOYAL}”.$