Katy Perry is playing three concerts in Singapore this year. The costs for renting out the 10,000-seat auditorium and other up-front expenses such as insurance, security, and publicity, will cost $60,000 for the entire Singapore trip. The costs for Kat and her band include a charge of $5,000 per concert plus 70% of the income from ticket sales. The concert promoter is expecting to sell out all three concerts and is offering two types of tickets - general and premier. General tickets cost $28 and offer admission to the open seating concert. Premier Tickets cost $36 and offer early entrance to the auditorium and a free t-shirt.
How many of each type of ticket does the promoter need to sell in order to make $20,000 in profit on opening night?
