Consider $K=3$ random variables $X,Y,Z$. Could you suggest a data generating process such that
(1) $X,Y,Z$ are pairwise independent
(2) $X,Y,Z$ are mutually dependent
(3) $X\sim U([0,1])$, $Y\sim U([0,1])$, $Z\sim U([0,1])$
Could you generalise to any $K>2$?