The number of square matrices of order 2 using numbers 1 and -1 exactly once and the number 0 twice is:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) - 12
We have 4 spaces
so no. of ways to fill them using numbers 1 and -1 exactly once and the number 0 twice is
$\frac{4!}{2!}=12$