Then number of all possible matrices of order 3 X 3 with each entry 0 and 1. I got the answer 512

But can any on elaborate the problem like A= 0 0 0

0 0 0

0 0 0

I got only 125 matrix I am not able to get 512.can any one help me by giving all possible mattix. Please please

The logic is, in matrix A total 9 elements are there and each element you can fill by 2 choices, so 9 places we can fill by 2 choices, hence 2*2*2...2(9 times) so 2^9 = 512 total number of possible matrices.
If you are doing in that way, you must have left few matrices, like one possible matrix is all entry with 0 only, the matrix you have written here, and then take only 1 element as 1 and rest 0, in that case you will get 9 different matrices, then take 2 one’s and rest 7 zeros in that case you wll get 36 matrices with different combination, simple way to eleaborate is the first method and practically if you dont left any case then definately you will get 512 matrices.