Assume that the number of child tickets on Saturday is x
Since the number of adult tickets is twice the number of the child tickets, then
The number of adult tickets is 2x
Since the child admission is $5.30
Since the adult admission is $9.30
Since the total amount of admission is $860.40, then
Multiply x by 5.30 and 2x by 9.30, then add the products and equate the sum by 860.40
[tex]5.30(x)+9.30(2x)=860.40[/tex]Simplify the left side
[tex]\begin{gathered} 5.30x+18.60x=860.40 \\ 23.90x=860.40 \end{gathered}[/tex]Divide both sides by 23.90
[tex]\begin{gathered} \frac{23.90x}{23.90}=\frac{860.40}{23.90} \\ x=36 \end{gathered}[/tex]The number of child tickets sold on Saturday was 36
