Put the squared deviation inside the expectation

Alex and his friend stand randomly in a queue with three other people. X is the number of people between Alex and his friend.

(i) Show that $P(X=2)=0.2$.

(ii) Tabulate the distribution of X.

(iii) Find $E(X)$ and $E[(X-1)^2]$. Hence find $\operatorname{Var}(X)$.