For any 3 × 3 matrix \( A \), if \( A(\mathrm{adj}\,A)=\begin{bmatrix}5&0&0\\0&5&0\\0&0&5\end{bmatrix} \), then \( 2|A| \) is equal to
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 10
For any square matrix, \( A(\mathrm{adj}\,A)=|A|\,I \). Here
\( A(\mathrm{adj}\,A)=5I \)
\( |A|=5 \)
\( 2|A|=10 \)
NCERT (2026-27 edition):
Adjoint and Inverse of a Matrix
