If A is a square matrix of order 3 and |A| = 5, then |adj(adj A)| is: |
125 625 75 375 |
625 |
The correct answer is Option (2) - 625 $\text{For an } n \times n \text{ matrix: } |\text{adj } A| = |A|^{n-1}$ $|\text{adj}(\text{adj } A)| = |\text{adj } A|^{n-1}$ $n = 3,\;\; |A| = 5$ $|\text{adj } A| = 5^{3-1} = 5^2 = 25$ $|\text{adj}(\text{adj } A)| = 25^{3-1} = 25^2 = 625$ $|\text{adj}(\text{adj } A)| = 625$ |