Question

If $A$ is a square matrix of order $3$ and $|A|=8$, then $|adjA|=$

• A. $8$
• B. $8^2$
• C. $1/8^2$
• D. $1/8$

Answer 1

Answer: (B)

$|A|=8,$ order of $A$ is 3.
We know that $|adjA|=|A{|}^{n-1}$
Here, $n=3$ and $|A|=8$
$\therefore |adjA|=8^{3-1}=8^2$.