Question:
If d is the determinant of a square matrix A of order n, then the determinant of its adjoint is
(a) $d^{n}$
(b) $d^{n-1}$
(c) $d^{n+1}$
(d) $d$
Solution:
(b) $d^{n-1}$
We know,
$|\operatorname{adj} A|=|A|^{n-1}$
$\Rightarrow|\operatorname{adj} A|=d^{n-1}$