Let the number of student tickets sold be s and the number of adult tickets sold be a.
(a) 10s+12a=146
(b) 15s+8a=139
(c) Multiplying the bottom equation by 1.5, we get [tex]22.5s+12a=208.5[/tex]. Subtracting this from the first equation, we get that [tex]12.5s=62.5[/tex], and thus s=5. So, if s=5, this means [tex]10(5)+12a=146[/tex], and thus a=8.
So, a student ticket costs $5 and an adult ticket costs $8.
