Answer:
The number of adult tickets are 57.
Step-by-step explanation:
Given,
Total number of tickets = 156
Total money = $1077.60
Solution,
Let the number of adult be x and of child be y .
So, Total number of tickets = Number of adults + Number of child

Now, according to question;
Total money = 

On multiplying by 10 on both side, we get;

Now multiplying equation 1 by 53 then subtract it from equation 3, we get;

Since x is the number of adults,
Number of adults=57
Number of child = y = 156-57=99
Thus the number of adult tickets are 57.