Answer: 40.
- A 40
- B 10
- C 5
- D 20
Correct answer: A. 40
Explanation: |kA| = kⁿ|A| for an n×n matrix, so |2A| = 2³ × 5 = 40.
Concept context
Evaluation of determinants, cofactors, adjoint, inverse of matrix, Cramer's rule and area applications. Always in board and JEE.