UoH 2021 Question 32: Random variables and standard distributions

Consider rolling of two fair dice (one White and one Blue), all outcomes being equally likely. Let $n_1$ be number that came up on the White die and let $n_2$ be the number that came up on the Blue die. Define the random variables: $Y = (n_2 - n_1)$; $Z = |n_2 - n_1|$. Let $\mu_Y$, $\mu_Z$ be means and $\sigma_Y^2$, $\sigma_Z^2$ be variances respectively of random variables $Y$ and $Z$. Then,