Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Matrices

Question:

If $A=\begin{bmatrix}n&0&0\\0&n&0\\0&0&n\end{bmatrix}$ and $B=\begin{bmatrix}a_1&a_2&a_3\\b_1&b_2&b_3\\c_1&c_2&c_3\end{bmatrix}$, then $AB$ is equal to

Options:

$B$

$nB$

$B^n$

$A+B$

Correct Answer:

$nB$

Explanation:

We have, $A =nI_3$

$∴AB=(nI_3) B=n (I_3 B) =nB$.