If the room is 10 by 12 that means each wall is 10 by 12 (I'm assuming) so the area of each wall is 120 ft and since there are 4 of them the total area of the walls is 480 ft and if wallpaper costs 1.53 per ft, it costs 480 * 1.53 or $734.40
because if a human is 3 meters tall and cast 2 times the length of himself then if a building casts 25 meters then it should be 2 times less than its shadow.
