Then one * * * has three! *8! grow
We can find out the probability that the phonetic serial numbers of two students in Class Two are not connected.
So I also regard the two people in Class Two as a whole.
One * * * has three! *2! *7! grow
So the probability that the phonetic serial numbers of two students in Class Two are not connected is 1-(3! *2! *7)! /(3! *8! )=3/4