Let A be a square matrix such that $A(adj. A) =\begin{bmatrix}4&0&0\\0&4&0\\0&0&4\end{bmatrix}$ then find the values of $|adj. A|$

14 12 16 18

16

We know that $A(adj. A) = |A|I_n$ $∴|A|=4$ $|adj. A|=|A|^2 = 4^2 = 16$