If $A = \{1, 2, 3, 4, 5, 6\}$ then which of the following is not true?

Consider the following statements
$r$: If $p \rightarrow q$ is false then $p \vee q$ is false.
$s$: If $p \leftrightarrow q$ is false then $p \vee q$ is false.
The truth values of $r \rightarrow s$ and $s \rightarrow r$ are respectively ____

In triangle ABC, with usual notations, if the angles are in Arithmetic Progression and $3c^2 = 2b^2$, then the measure of angle A is

If $A = \begin{bmatrix} 0 & 0 & -1 \\ 0 & -1 & 0 \\ -1 & 0 & 0 \end{bmatrix}$ then which of the following is true ?