Question

Order of the matrix $\begin{bmatrix} 1 & 6 \\ 2 & 0 \\ 7 & -1 \end{bmatrix}$ is

• A. $1 \times 3$
• B. $3 \times 2$
• C. $2 \times 2$
• D. $3 \times 3$

Hint:

A common mistake is swapping the order of rows and columns. Just remember the mnemonic "RC" (like Remote Control or Roman Catholic) to always put Rows first and Columns second.

Answer 1

The Correct Option is B

1. Identifying Rows: Rows are the horizontal arrangements of elements. Looking at the matrix:

• Row 1: $[1 \quad 6]$

• Row 2: $[2 \quad 0]$

• Row 3: $[7 \quad -1]$
Thus, the total number of rows ($m$) is

3.

2. Identifying Columns: Columns are the vertical arrangements of elements. Looking at the matrix:

• Column 1: $\begin{bmatrix} 1 \\ 2 \\ 7 \end{bmatrix}$

• Column 2: $\begin{bmatrix} 6 \\ 0 \\ -1 \end{bmatrix}$
Thus, the total number of columns ($n$) is

2.

3. Defining the Order: The order of a matrix is conventionally written as $m \times n$ (read as "$m$ by $n$"). Substituting our values: $$\text{Order} = 3 \times 2$$ Therefore, the matrix has 3 rows and 2 columns, making the correct order $3 \times 2$.