Answer:
170 tickets.
Step-by-step explanation:
Write formulas for the question.
[tex]N_2+N_3=400[/tex]
[tex]2N_2+3N_3=1030[/tex]
Then use substitution.
[tex]N_2=-N_3+400[/tex]
[tex]2(-N_3+400)+3N_3=1030[/tex]
[tex]-2N_3+800+3N_3=1030[/tex]
[tex]N_3=230[/tex]
So number of $3 tickets sold is 230. But they ask for the tickets bought in advance (i.e. the tickets sold for $2). Use substitution again.
[tex]N_2+230=400\\N_2=400-230\\N_2=170[/tex]