6.3
1 Bill and Rose like classical music.
2 Carol doesn't like classical music.
3 I like classical music.
4 Bill and Rose don't like boxing.
5 Carol likes boxing.
6 I don't like boxing.
7 Bill and Rose don't like horror films.
8 Carol likes horror films.
9 I don't like horror films.
10 Bill and Rose like dogs.
11 Carol doesn't like dogs.
12 I like dogs.