Question

If matrix
\[ A = \begin{bmatrix} 3 & -2 & 4 \\ 1 & 2 & -1 \\ 0 & 1 & 1 \end{bmatrix}, \quad \text{and} \quad A^{-1} = \frac{1}{k} \, \text{adj}(A), \]
then \(k\) is:

• A. 7
• B. \(-7\)
• C. 15
• D. -11

Hint:

Always relate inverse with determinant using:
\[ A^{-1} = \frac{1}{\det A} \, \text{adj}(A) \]

Answer 1

The Correct Option is A