Answer:
58 child tickets were sold
Explanation:
If 58 child tickets were sold, then that would mean that 77 adult tickets were sold because they need to add up to 135 total tickets sold.
We can multiply 58 by $6 to get the total sales for just the child tickets which will give us $348.
Next, we can multiply 77 by $9.60 to get the total sales for the adult tickets which will give us $730.20
Then when we have both of our sales for the children tickets and the adult tickets, we can add them together to get a total amount of sales of $1087.20
(sorry if this is confusing but I hope this helped!)