Let:
x = Number of tickets
a = Price of each ticket
T = Total amount of money
so:
[tex]\begin{gathered} T=ax \\ \end{gathered}[/tex]Since nine tickets were refunded,
let:
y = Number of tickets refunded.
[tex]\begin{gathered} T=ax-ay \\ where\colon \\ a=11.75 \\ x=342 \\ y=9 \\ so\colon \\ T=11.75(342)-11.75(9) \\ T=4018.5-105.75 \\ T=3912.75 \end{gathered}[/tex]Answer:
$3912.75