What would the perfect square be???

Aschool puts on a play. the play costs $1,200 in expenses. the students charge $4.00 for tickets. there will be one performance of the play in an auditorium that seats 500 people. what is the domain of the function that shows the profit as a function of the number of tickets sold?  

Can someone me out here and the tell me the greatest common factor

Solve this problem! extra ! 3025/5.5 = a/90.75 / = fraction