Question:
For a $2 \times 2$ matrix $A=\left[a_{i j}\right]$ whose elements are given by $a_{i j}=\frac{i}{j}$, write the value of $a_{12}$.
Solution:
Here,
$a_{i j}=\frac{i}{j}$
$1 \leq i \leq 2$
$1 \leq j \leq 2$
$\Rightarrow a_{12}=\frac{1}{2}$
Therefore, the value of $a_{12}$ is $\frac{1}{2}$.