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)
Presume thats 18 inches square tiles, then each tile = 1.5 * 1.5 = 2.25 sq ft > So, 200 / 2.25 = 88.88 tiles
Tiles that are two feet on a side cover 4 square feet. 378 of them cover 1512 square feet.
192 tiles
Since a 12x12 tile is one square foot, then 38 12x12 tiles will cover 38 square feet.
Two tiles will suffice since they will cover 36 square feet.
Each tile covers 4 square feet. You will need 24.75 tiles to cover the area.
67 tiles.
76.6 tiles
190
It will require a minimum of 1,462 tiles. That number will cover about 1,850.34 square feet.
If the 6x12 tiles are in inches, it will take two of them to cover a square foot. You will need 210 of them.
You will need at least 67 tiles. This will cover 150.75 square feet.