Question

Let X be a matrix of order $2 \times n$ and Z be a matrix of order $2 \times p$. If n = p, then the order of the matrix $7X - 5Z$ is

• A. $p \times 2$
• B. $2 \times n$
• C. $n \times 3$
• D. $p \times n$

Answer 1

Answer: (B)

$2 \times n$

Answer 2

The order of matrix X is $2 \times n$, The order of matrix Z is $2 \times p$ 7X - 5Z is defined when X and Z of the same order $\Rightarrow \, n = p$ Thus the order of 7X - 5Z is $2 \times n$.