The costumer has to choose 2 out of 3 appetizers, 4 out of 10 main courses and 2 out of 4 desserts.
For each of these choices, there are
[tex]\displaystyle \binom{3}{2}=3,\quad \binom{10}{4}=210,\quad \displaystyle \binom{4}{2}=6[/tex]
possible choices.
So, the costumer has a total of
[tex]3\cdot 210 \cdot 6=3780[/tex]
possible choices.