Write the following intervals in set-builder form :
$\left[ {6,12} \right]$
Which of the following are sets ? Justify your answer.
A team of eleven best-cricket batsmen of the world.
Which of the following are examples of the null set
Set of odd natural numbers divisible by $2$
Let $A=\{1,2,\{3,4\}, 5\} .$ Which of the following statements are incorrect and why ?
$\{\varnothing\} \subset A$
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 $A \subset B$ and $x \notin B,$ then $x \notin A$