A benefit concert is being held at a nearby venue that charges $500 for rental of the space. Additionally, they are charging $5 per person who attends. The costs are to be split up between all of the attendees except there are 5 members of the family that the event is benefiting, so you do not want them to have to pay. How many people would need to attend in order for the ticket price to be $15? Set up and solve an equation to determine this ticket price.