Answer:
327
Explanation:
Let s represent the number of student tickets sold. Then total revenue is ...
1.75s + 2.50(585-s) = 1217.25
Subtracting 1217.25 and collecting terms, we have ...
-0.75s +245.25 = 0
Dividing by 0.75 gives ...
-s + 327 = 0
s = 327 . . . . . . . add s to both sides of the equation
327 tickets were student tickets.