A, 2. 35 times 55 represents the area, and that equals 1925. Subtract the 1250 from one bag from the 1925 you need to cover the area (do 1925-1250) to find how much more you need after using one bag. That gets you 675, so you'll need one more bag to cover that for 2 bags in total. The second bag will put you over the 675 you need, but that's ok because now you have enough to cover the 1925 sq foot area.
