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Let A be a 3 × 3 matrix such that |adj(adj(adjA))| = 81. If S = , | A | |) ) adjA ( adj (| : Z n ) 4 n 5 n 3

1. 1 n ( 2 2 ⎪ ⎭ ⎪ ⎬ ⎫ ⎪ ⎩ ⎪ ⎨ ⎧ = ∈ − − − then ∑ ∈ + S n ) n n ( | A | 2 is equal to
2. 750
3. 866
4. 732 (4) 820

Correct answer: 866

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