The answer is: 250 adult tickets were sold.
To be safe, prove that your answer is correct.
If there are 74 more student tickets than adult tickets, the amount of adult tickets must obviously be less.
Explanation:
74 more than 250, or 250+74 is 324.
250+324=574.
Now, you know the answer is correct. It satisfies all of the given conditions.
Also, note that the difference between the number of student tickets and adult tickets is 74.
So, there are 250 adult tickets and 324 student tickets.