Q.

If a matrix has 8 elements, then which of the following will not be a possible order of the matrix

1 1 × 8  
2 2 × 4  
3 4 × 2  
4 4 × 4  

Ans.

(4)

Ans.    4 × 4

Explanation:

We know that if a matrix is of order m×n, then it has mn elements. Thus, to find all possible orders of a matrix with 8 elements, we will find all ordered pairs of natural numbers whose product is 8. Thus, all possible ordered pairs are (1, 8), (2, 4), (4, 2).