If A is an invertible matrix of order 3 and |A|

Given:

$A$ is an invertible matrix of order 3

$|A|=5$

As we know,

$\operatorname{adj}(\operatorname{adj} A)=|A|^{n-2} A$, where $n$ is the order of $A$

$\Rightarrow \operatorname{adj}(\operatorname{adj} A)=|A|^{3-2} A \quad(\because$ Order of $A$ is 3$)$

$\Rightarrow \operatorname{adj}(\operatorname{adj} A)=|A|^{1} A$

$\Rightarrow \operatorname{adj}(\operatorname{adj} A)=5 A \quad(\because|A|=5)$

$\Rightarrow \operatorname{adj}(\operatorname{adj} A)=5 A$

Hence, $\operatorname{adj}(\operatorname{adj} A)=\underline{5 A} .$