7) The Meadow Brook Amphitheatre has 3 different seating options. Seats in section A cost $75 each, seats in section B cost $55 each, and lawn seats cost $30 each. There are three times as many seats in Section B as in Section A. If the theatre sold out all 23,000 seats and took in a revenue of $870,000, how many seats are in each section? Help please, with explanation??​