Question

If $A$ is a square matrix of order $3$ and $|A|=5$, then $|Aadj.A|$ is

• A. 5
• B. 125
• C. 25
• D. 625

Answer 1

Answer: (B)

$|A$ adj $A|=|A||$adj $A|$
$=|A||A{|}^{3-1}$
$=5\cdot 5^2$
$=125$