420.
Get 450 to be safe.
35
5,290 Pieces
Depends on the size of the tiles.
It depends on the dimension used for measuring the tiles. Whether they are 12 in x 12 in or 12 cm x 12 cm will make a huge difference to the number of tiles required!
8 ft 6 in X 12 ft = 102 sq ft 102 sq ft X 4 tiles/sq ft = 408 tiles Get a few extra in case some crack. You may be glad later that you had a few replacement tiles.
35
144 assuming no waste.
41
12 tiles by 18 tiles or 216 tiles total
144/(1.5*1.5) = 64 tiles, but if you are using this to determine how many are needed to tile a room, you need to add at least 10% for edging around the room. So, you probably need at least 71 or more tiles.
Floor area = 12 ft x 18 ft = 216 square feet. There are 4 six-inch square tiles needed for each square foot, so 864 tiles are needed.
You will need 25, 13x13 tiles.
A 13 x 13 tile is 1.74 sq ft. 144/1.74 = 123 tiles
291.43 tiles
Without any waste you would need 25 tiles.
176 tiles
It depends on whether the tiles are 18 inch * 18 inch or 18 cm * 18 cm, etc. And also on whether the room is 10ft *10ft or 10 yards*10 yards or 10 metres*10 metres etc.