Discrete uniform distribution

Roll a fair $n$-sided die, how likely it lands on any given number?

$$ p(k) = \begin{cases} 1/n, & \text{if $k = a, a+1, \cdots, b-1, b$,} \\ 0, & \text{otherwise.} \end{cases} \\[16pt] \text{where $n=b-a+1$.} $$