If a matrix has 28 elements, what are the possible orders it can have? What if it has 13 elements?
We know that, if a matrix has an order m × n, it has mn elements, where m and n are natural numbers.
We have, m × n = 28
⇒ (m,n) = {(1,28),(2,14),(4,7),(7,4),(14,2),(28,1)}
So, the possible orders are 1 × 28, 2 × 14,4 × 7,7× 4,14 × 2,28 × 1.
Also, if it has 13 elements, then m × n =13
⇒ (m,n) = {(1,13).(13,1)}
Hence, the possible orders are 1× 13, 13×1.