Blaircraft Company manufactures a product which requires five pounds of raw material for each unit produced. For the next year, beginning inventory of raw materials is 8,000 pounds. The raw materials inventory at the end of each quarter should be 15% of the next quarter's raw materials needed for production. Given the projected production in units below, what is the quantity of raw materials which need to be purchased for the third quarter?

quarter 1, 7000lbs 2, 5000lbs 3, 8000lbs 4, 6000lbs