If $A$ be a $3 \times 3$ square matrix such that $A(\text{adj } A) = \begin{bmatrix} 5 & 0 & 0 \\ 0 & 5 & 0 \\ 0 & 0 & 5 \end{bmatrix}$ then the value of $|\text{adj } A|$ is
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 25 ##
$A(\text{adj } A) = 5I$
$A(\text{adj } A) = |A|I$
$∴|A| = 5$
$|\text{adj } A| = |A|^{n-1} = |A|^2 = 25$