Final answer:
76 adult tickets were sold.
Step-by-step explanation:
Let's assume the number of adult tickets sold is x. Since the number of student tickets sold was three times the number of adult tickets sold, we can represent it as 3x.
According to the problem, the total number of tickets sold was 304. So, we can write the equation:
x + 3x = 304
Combining like terms, we get:
4x = 304
Divide both sides by 4:
x = 76
Therefore, 76 adult tickets were sold.