Answer
The matrix is, $ A=\left[ \begin{array}{*{35}{r}}
2 & 2 & 2 \\
1 & 2 & 1 \\
1 & 2 & 1 \\
\end{array} \right]$
Work Step by Step
Consider the rectangular boxes:
$\begin{matrix}
{{a}_{11}} & {{a}_{12}} & {{a}_{13}} \\
{{a}_{21}} & {{a}_{22}} & {{a}_{23}} \\
{{a}_{31}} & {{a}_{32}} & {{a}_{33}} \\
\end{matrix}$
To form a digital photograph of the letter T with dark gray letters, we color the boxes ${{a}_{11}},{{a}_{12}},{{a}_{13}},{{a}_{22}},{{a}_{32}}$ with dark gray. We use a light gray background for the other boxes, like so:
$\begin{matrix}
2 & 2 & 2 \\
1 & 2 & 1 \\
1 & 2 & 1 \\
\end{matrix}$
Thus, the required matrix representing the letter is, $ A=\left[ \begin{array}{*{35}{r}}
2 & 2 & 2 \\
1 & 2 & 1 \\
1 & 2 & 1 \\
\end{array} \right]$.
