Question -
Answer -
Since, a matrix having 
elementis of order 
(i) Therefore, there are 6 possible matrices having 18elements of orders 1 x 18, 2 x 9, 3 x 6, 18 x 1, 9 x 2, 6 x 3.
(ii) Prime number 5 = 1 x 5 and 5 x 1
Therefore, there are 2 possible matrices of order 1 x 5 (Rowmatrix) and 5 x 1 (Column matrix).