If $A (adj\, A)= \begin{bmatrix}-5&0&0\\0&-5&0\\0&0&-5\end{bmatrix}$, then the value of $|A|$ is
Answer & explanation
Correct answer: option 2
$A (adj\, A)=|A|I$
as $A (adj\, A)=\begin{bmatrix}-5&0&0\\0&-5&0\\0&0&-5\end{bmatrix}=-5\begin{bmatrix}1&0&0\\0&1&0\\0&0&1\end{bmatrix}$
$⇒|A|=-5$