Let $A = \{0, 3, 4, 6, 7, 8, 9, 10\}$ and $R$ be the relation defined on $A$ such that $R = \{(x, y) \in A…

Given,

Set $A=\left\{10,9,8,7,6,4,3,0\right\}$

Now relation $x-y\text{ is odd or} x-y=2$ can be given by,

$\left\{R=(10,9),(10,8),(10,7),(10,3),(9,8),(9,7),(9,6),(9,4),(9,0),(8,7),(8,6),(8,3),(7,6),(7,4),(7,0),(6,4),(6,3),(4,3),(3,0)\right\}$

So, total there are $19$ elements and all the elements of $R, (a, b)$ are of type $a > b$.

Hence, we need to add total of $19$ more elements to $R$ to make in symmetric