The drama club is selling tickets to their play to raise money for the show's expenses. Each student ticket sells for $7.50 and each adult ticket sells for $10. The auditorium
can hold at most 90 people. The drama club must make no less than $750 from ticket
sales to cover the show's costs. Also, they must sell no less than 20 student tickets and
at most 60 adult tickets. If x represents the number of student tickets sold and y
represents the number of adult tickets sold, write and solve a system of inequalities
graphically and determine one possible solution.