The Tile company tiles rectangle areas. Ted lays the center tiles. Mary comes along and borders the area with gray tiles. ( For example, in a 1x3 area, Ted would lay the three center tiles and Mary would lay the 12 border tiles.)
Picture in this example a rectangle that is 3 square tiles by 5 square tiles in the border are gray , and the 3 square tiles in the middle are white.
Suppose each tile is one square meter( unite area)
How many boarder tiles are needed for a 4x8 area( to be bordered)?
A 28X56 area ( to be bordered)?
A X x Y area ( to be bordered)?