Question

If $A$ is any square matrix of order $3\times 3$ then $|3A|$ is equal to

• A. $3|A|$
• B. $\frac{1}{3}|A|$
• C. $27|A|$
• D. $9|A|$

Answer 1

Answer: (C)

We know that, if $A$ is any square matrix of order $n$,
then $|KA|=K^n|A|$
$\therefore |3A|=3^3|A|[\because$ order of $A=3]$
$=27|A|$