Question

For a 3 X 3 matrix A, if det A = 4, then det (Adj. A) equals

• A. $-4$
• B. $4$
• C. $16$
• D. $64$

Answer 1

The correct option is C $16$

$3\times J$ Matrix , $\left|A\right|=4$

We know that $\left|adjA\right|={\left|A\right|}^{n-1}$

here $n=3$

So, $\left|adjA\right|=4^2=16$