5.5 inches = 5.5/12 foot.
Total area of all those tiles is (324) x (5.5/12 x 5.5/12) = 68.0625 square feet
It is not clear what is meant by an "18x18 square feet" tile. 18ft * 18 ft = 324 square feet, so that one tile will be more than enough. An 18 inch by 18 inch tile cannot be a 18x18 square feet tile.
That depends on the unit of measurement for the tiles. Assuming the tiles are 18 inches by 18 inches, one tile is 324 square inches = 2.25 square feet. Multiply by 106 to get 238.5 square feet. If the tiles are 18 feet by 18 feet (pretty big tiles, but hey, it could happen), one tile is 324 square feet, so 106 pieces of that would be 34344 square feet.
324 square feet.
324 square feet.
324 square feet.
Assuming you mean 18 inch tiles... 290 square feet is 41,760 square inches. Each tile is 324 square inches - so you would need 129 tiles in total (with a fraction of a tile left over)
36*9 = 324 square feet
36 square yards = 324 square feet.
324 square feet. Multiply the two dimensions - the result is the number of square feet.
36 square yards. (divide square feet by 9 to get square yards).
18 x 18 = 324 square feet
324 square feet. Multiply length by width - the result is the area in square feet.