Kamrie wants to paint her living room. The rectangular room measures 20 feet by 15 feet and has 10-foot ceilings. Along one of the long walls, there are three windows that each measure 3 feet by 8 feet. Along one of the short walls, there are two windows that each measure 3 feet by 8 feet. Along the other long wall, there is a rectangular opening that measures 7 feet by 8 feet. The cans of paint Kamrie will purchase cover 415 square feet. Determine the area that Kamrie will paint and then determine how many cans of paint Kamrie needs to buy.