Answer: There were 40 adult tickets and 28 children's tickets
Explanation:
Let x represent the number of adult tickets sold.
Let y represent the number of children's tickets sold.
An event sold $608 worth of tickets adult tickets cost $11 while children's tickets cost $6. It means that
11x + 6y = 608 - - - - - - 1
If 68 tickets were sold, it means that
x + y = 68
Substituting x = 68 - y into equation 1, it becomes
11(68 - y) + 6y = 608
748 - 11y + 6y = 608
- 11y + 6y = 608 - 748
- 5y = 140
y = 140/5 = 28
x = 68 - y = 68 - 28
x = 40