Let $A = \{1, 2, \{3, 4\}, 5\}$. Which of the following statements are incorrect and why?
$1 \in A$

Write the following set in roster form:
$F =$ The set of all letters in the word $BETTER$

Which of the following is an example of the null set?
$\{ y : y \text{ is a point common to any two parallel lines} \}$

Prove that for any sets $A$ and $B$,$A \cap (A \cup B) = A$.

From the sets given below,select equal sets:
$A=\{2,4,8,12\}, B=\{1,2,3,4\}, C=\{4,8,12,14\}, D=\{3,1,4,2\}$
$E=\{-1,1\}, F=\{0, a\}, G=\{1,-1\}, H=\{0,1\}$

$A$ graph $G$ has $m$ vertices of odd degree and $n$ vertices of even degree. Then which of the following statements is necessarily true?