Assuming you mean 18 inch by 18 inch, you will need 133 and 1/3 tiles.
You'll need 200 18-inch tiles.
You will need at least 67 tiles. This will cover 150.75 square feet.
You would need 100 tiles - and have some fragments left over.
500 square feet = 500*12*12 square inches this will require 500*12*12/(18*18) tiles = 222.22 tiles. This assumes that all parts of cut tiles are used. If not, the exact dimensions of the area are required.
Assuming you mean 18 inch by 18 inch, you will need 133 and 1/3 tiles.
You'll need 200 18-inch tiles.
It depends on the units used for measuring the tiles. Obviously, the number of 18 inch x 18 inch tiles required will not be the same as 18 cm x 18 cm tiles. And if there were 18 yard x 18 yard tiles, you would need only 1.
18*18 is 324in2. This is 0.25 square yards. So you need 4 tiles
You will need at least 67 tiles. This will cover 150.75 square feet.
360 tiles.
You would need 100 tiles - and have some fragments left over.
236 18-inch tiles.
500 square feet = 500*12*12 square inches this will require 500*12*12/(18*18) tiles = 222.22 tiles. This assumes that all parts of cut tiles are used. If not, the exact dimensions of the area are required.
18 10x10-inch tiles.
18" x 18" = 1.5' x 1.5' = 2.25 square feet90/2.25 = 40 tiles.
18*18-324 319 square feet = 391*12*12 inches = you solve it yourself.