Answer: O(n 3 ).
- A O(n)
- B O(n<sup>2</sup>)
- C O(n<sup>3</sup>)
- D O(2<sup>n</sup>)
Correct answer: C. O(n<sup>3</sup>)
Explanation: Gaussian elimination performs forward elimination (≈n³/3 multiplications) and back substitution (≈n²/2). Dominant term is n³, giving time complexity O(n³). Doubling n increases work roughly 8-fold. Answer: O(n³).
Concept context
Evaluation of determinants, cofactors, adjoint, inverse of matrix, Cramer's rule and area applications. Always in board and JEE.