Which of the following are sets ? Justify your answer.
The collection of ten most talented writers of India.
The collection of ten most talented writer of India is not a well-defined collection because the criteria for determining a writer's talent vary from person to person.
Hence, this collection is not a set.
Let $A$ and $B$ be two non-empty subsets of a set $X$ such that $A$ is not a subset of $B$, then
Write down all the subsets of the following sets
$\{ 1,2,3\} $
For an integer $n$ let $S_n=\{n+1, n+2, \ldots \ldots, n+18\}$. Which of the following is true for all $n \geq 10$ ?
From the sets given below, select equal sets:
$A=\{2,4,8,12\}, B=\{1,2,3,4\}, C=\{4,8,12,14\}, D=\{3,1,4,2\}$
$E=\{-1,1\}, F=\{0, a\}, G=\{1,-1\}, H=\{0,1\}$
Let $A=\{1,2,\{3,4\}, 5\} .$ Which of the following statements are incorrect and why ?
$\{1,2,3\}\subset A$