Four people come to a party and shake hands with each other. if each person shakes the hand of every other person, how many handshakes occur?

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?