Opening the paper…
The joint pmf of and is
Are and independent?
The joint pmf of $X$ and $Y$ is $$\begin{array}{c|cc} X\\backslash Y & 1 & 2 \\ \hline 0 & 0.3 & 0.2 \\ 1 & 0.3 & 0.2 \end{array}$$ Are $X$ and $Y$ independent? The joint pmf of $X$ and $Y$ is $$\begin{array}{c|ccc} X\\backslash Y & 1 & 2 & 3 \\ \hline 0 & 0.05 & 0.05 & 0.3 \\ 1 & 0.05 & 0.3 & 0.25 \end{array}$$ Are $X$ and $Y$ independent? The joint pmf of $X$ and $Y$ is $$\begin{array}{c|ccc} X\\backslash Y & 1 & 2 & 3 \\ \hline 0 & 0.1 & 0.04 & 0.06 \\ 1 & 0.3 & 0.12 & 0.18 \\ 2 & 0.1 & 0.04 & 0.06 \end{array}$$ Are $X$ and $Y$ independent?