The question isn’t really detailed that well, but assuming that you only need to paint 4 walls, you’ll need enough paint to cover 175•4 feet. Which is 700ft of paint. Since 2 quarts covers 175 feet you’ll need 8 quarts to cover 700 feet. But it says you want to apply TWO coats of paint of all the walls. So the answer is 16 quarts of paint.