Question

The number of all possible matrices of order 3 $\times$ 3 with each entry 0 or 1 is

• A. 18
• B. 512
• C. 81
• D. none of these

Answer 1

Answer: (B)

512

Answer 2

There are in total 9 entries and each entry can be selected in exactly 2 ways. Hence, the total number of all possible matrices of the said type is $2^9$.