Answer:
First let's measure how many ways can be the announcement done.
We have 9 people. So 9 options for first person and 8 option for the second.We get 72 possibilities. Since it doesn't matter a is with b or b is with a the possibilities go down to 36.
Now let's count how many ways we can make 2-girl pair
we can 5 options for the first person and 4 options for second. The same way divide this by 2 we are left with 10 possibilities.
So we got that there are 36 pairs possible.
At least find the probability divide the wanted outcome by the possible numbers of outcomes. 10/36=5/18
Answer 5/18