5. In a cube, the probability that 3 randomly chosen edges are pairwise skew is $\qquad$

In a cube, randomly select 3 edges, the probability that they are pairwise skew is $\qquad$
A cube has 12 edges in 3 directions (left-right, up-down, front-back), with 4 edges corresponding to each direction. Taking any edge (in the front-back direction), there are 2 edges in the up-down direction that intersect with it, giving 2 choices for the up-down direction. This leaves 3 edges in the left-right direction that intersect with the selected 2 edges, leaving only 1 choice, thus there are 8 ways to satisfy the condition. The number of ways to randomly select 3 edges from the 12 edges of the cube is $C_{12}^{3}=220$. Let $A=$ “randomly selecting 3 edges from a cube such that they are pairwise skew”, so $P(A)=\frac{8}{220}=\frac{2}{55}$.