Answer: 95 adult tickets and 40 child tickets were sold.
Step-by-step explanation:
Let x represent the number of adult tickets that were sold.
Let y represent the number of child tickets that were sold.
The cost of an adult ticket is $12 and the cost of a child ticket is $5.
The ball game sold $1,340 in tickets one Saturday. It means that
12x + 5y = 1340- - - - - - - - - - 1
The number of $12 adult tickets was 15 more than twice the number of $5 child tickets. It means that
x = 2y + 15
Substituting x = 2y + 15 into equation 1, it becomes
12(2y + 15) + 5y = 1340
24y + 180 + 5y = 1340
24y + 5y = 1340 - 180
29y = 1160
y = 1160/29
y = 40
x = 2y + 15 = 2 × 40 + 15
x = 95
