The answer depends on the measurement units used for 18x18.
start with 38 tiles.
118
6' x 9' (54 square feet) = 6 square yards of tiles needed.
56 16x16" tiles are needed.
The answer depends on the measurement units used for 18x18.
266.666666666 so rounding up 267 tiles.
192 tiles
67 tiles.
start with 38 tiles.
220
10
100 tiles or 96 which is the correct amount
102.22 tiles because each tile is 2.25 sq.ft. 230 / 2.25 =102.22 so really 103 tiles.
288
118
You'll need 200 18-inch tiles.