Question

What is the total number of 2 × 2 matrices with each entry 0 or 1?

Answer 1

In a 

\[2 \times 2\] matrix, the total number of elements are 4 and each entry can be written in 2 ways.

Number of ways in which 4 entries can be written =

\[4^2 = 16\]  [Applying the above property]