John is using square ceramic floor tiles that are each 18 inches long. how many of these tiles will john need to cover a floor with an area of 81 square feet? site:

First we need to convert the square feet to square inches

1 square feet = 144 square inches

Therefore, 81 square feet = 81*144 = 11,664 square inch

Each square tile is 18 inches long. Since its a square, the area of each tile = 18*18 = 324 square inch

So, the number of tiles required to cover the entire floor = total area of the floor in square inches / area of the tile in square inches

The number of tiles required to cover the entire floor = 11,664/324 = 36 tiles

The number of tiles required to cover the entire floor = 36 tiles