Answer:
99 ways
Explanation:
Let's say the the 11 courses are labeled a, b, c, d, ect. The possible chances of A bieng combined with another 9 appetisers is 9. Then B is combined with 9 appetisers. The C is combined with 9 appetisers and so on and so on. Meaning of there are 9 appetisers you times it by 11 main courses it means there will be 99 ways to make two course mean with one appetiser and one main course.
I am not 100% sure this is correct but this is what I think.