math
posted by jeremy .
a rectangular mosaic is made up of exactly 12 square tiles that have an area of 9 square inches each. If the width of the mosaic is 9 inches, what is the perimeter of the mosaic in inches

Each tile is 3 by 3 inches
The width of the mosaic is 3 tiles. The length must be 4 tiles = 12 inches
P = 2L + 2W
P = 2(12) + 2(9)
P = 24 + 18
P = 42 inches