Question 158
In a basketball tournament 8 teams are divided into two groups of 4 teams each. At the end of the preliminary matches, the semi-finals will be played, in which the first place in the first group will meet the second place in the second group and the first place in the second group will meet the second place in the first group. If the teams in the first group are $A, B, C, D$ and the teams in the second group are $E, F, G, H$, what is the probability that the semifinal matches will be $A$ versus $E$ and $B$ versus $G$? (It is assumed that all possible rankings in each group are equally probable).