Answer: 100 tickets.
Step-by-step explanation:
- Number of $8 tickets sold = x
- Number of $12 tickets sold = y
Set up two equations: one representing total amount sold and another representing total dollars earned.
[tex]\left \{ {{x+y=215} \atop {8x+12y=2180}} \right.[/tex]
Rearrange x + y = 215 and find the value of x:
[tex]x+y=215\\x=215-y[/tex]
Substitute it into the other equation and solve for y:
[tex]8x+12y=2180\\8(215-y)+12y=2180\\1720-8y+12y=2180\\4y=2180-1720\\4y=460\\y=\frac{460}{4} =115[/tex]
Substitute in the y-value to the other expression to find x:
[tex]x+y=215\\x+115=215\\x=215-115=100[/tex]
Therefore, they sold 100 of the $8 tickets.
