Question

The rank of $\begin{bmatrix} 1 & 2 & 3 \\ 2 & 4 & 6 \\ 3 & 6 & 9 \end{bmatrix}$ is equal to

• A. 1
• B. 2
• C. 3
• D. None of these.

Answer 1

Answer: (A)

1

Answer 2

1 & 2 & 3 \\ 2 & 4 & 6 \\ 3 & 6 & 9 \end{bmatrix}$$ $$\begin{matrix} R_{21}( - 2) \\ \sim \\ R_{31}( - 3) \end{matrix}\begin{bmatrix} 1 & 2 & 3 \\ 0 & 0 & 0 \\ 0 & 0 & 0 \end{bmatrix}\therefore p(A) = 1$$