Let $A=\{1,2,\{3,4\}, 5\} .$ Which of the following statements are incorrect and why ?
$\{1,2,3\}\subset A$
State which of the following sets are finite or infinite :
$\{ x:x \in N$ and $(x - 1)(x - 2) = 0\} $
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 $x \notin A$
Write the following sets in the set-builder form :
$\{ 3,6,9,12\}$
List all the elements of the following sers :
$B = \{ x:x$ is an integer $; - \frac{1}{2} < n < \frac{9}{2}\} $