The number of proper subsets of the set $\{1, 2, 3\}$ is
$8$
$6$
$7$
$5$
Write the set $\left\{\frac{1}{2}, \frac{2}{3}, \frac{3}{4}, \frac{4}{5}, \frac{5}{6}, \frac{6}{7}\right\}$ in the set-builder form.
Show that the set of letters needed to spell $"\mathrm{CATARACT}"$ and the set of letters needed to spell $"\mathrm{TRACT}"$ are equal.
Write the following sets in the set-builder form :
$\{ 1,4,9 \ldots 100\} $
Let $A=\{1,2,\{3,4\}, 5\} .$ Which of the following statements are incorrect and why ?
$\{1,2,5\}\in A$
List all the elements of the following sers :
$C = \{ x:x$ is an integer ${\rm{; }}{x^2} \le 4\} $