Can someone pleaseee help but only do the circled ones

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?  

Ineed to know the answer to this algebra question.

Ron has 8 caps and 4 of his caps are blue. thes rest of his cap are red. how many of ron's caps are red