Answer
94 adult tickets were sold.
215 children tickets were sold.
Step-by-step explanation
Let the number of adult tickets sold be x
Let the number of children tickets sold be y
On the first day, 309 tickets in total wer sold
x + y = 309
And a total of 2203 dollars was made
12x + 5y = 2203
Bringing the two equations together and solving simultaneously
x + y = 309
12x + 5y = 2203
x = 94
y = 215
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