Answer:
300 adults, 200 students
Explanation:
1) Let the number of adult tickets sold be 
 , so the number of student tickets sold is
, so the number of student tickets sold is 

2) Adult tickets are $20 each so the amount of money made from these 

3) Student tickets are $5 each so the amount of money made from these 
4) Because $7000 was made in total, we have 

5) Solving this, we obtain 

6) So the number of adults was 
 , and the number of students was
, and the number of students was 
