Question

If a matrix has 18 elements, what are the possible orders it can have? What, if it has 5 elements?

Answer 1

Since, a matrix containg 18 elements can have any one of the following orders:
$1\times 18,18\times 1,2\times 9,9\times 2,3\times 6,6\times 3$
Similarly, a matrix containing 5 elements can have order $1\times 5or5\times 1.$