A certain rectangular wall is 12 feet high and 8 feet long.

Distraction: "Each tile consists of 16 smaller squares, each with sides of length 4 inches . . ."

Focus instead on the 16x16 tiles.

-- "each [large 16x16] tile" per the pattern in the diagram, has 4 smaller blue tiles.

-- find the number of large (16x16) tiles that will fit into the area of the wall. Multiply that number by 4 to get the number of blue tiles.

I converted and divided the way I did to avoid huge numbers.*

1) Convert feet to inches for wall height and length

Wall height = 12 feet =
12 feet * 12 inches/1foot = 144 inches

Wall length = 8 feet * 12 inches/foot = 96 inches

2)Calculate how many tiles will fit: Divide height and length of wall, respectively, by length of one side of a tile

Length of one side of a tile = 16 inches

So the height will have 144 in/16 in = 9 tiles (that will form 9 rows)

Length will have 96 in/16 in = 6 tiles (that will form 6 columns)

Total number of tiles is 9 * 6 = 54 tiles

3) How many blue tiles total?

There are 4 blue tiles on one big tile.
4 blue tiles * 54 big tiles = 216 blue tiles

Answer B

*I did not use these calculations when doing the problem, but here is the arithmetic with no "shortcuts":

Wall area (where 12 feet = 144 inches and 8 feet = 96 inches) --> 144 in * 96 in = 13,284 sq in
Tile area = 16 in * 16 in = 256 sq in

Wall area/tile area = # of tiles that will fit

13,284 sq in/256 sq in per tile = 54 tiles

54 tiles * 4 blue per tile = 216 blue