647
Nine square feet is equal to 3.24 20-inch tiles.
20 inches = 1.666 feet 1.66x 1.666 = 2.777 sq feet 78/2.777 = 28 tiles
20" = 2.78 square feet. Now divide the area of the tiles into the area of the room. 140/2.78 = 51 tiles
There are 4 6X6 tiles per sq foot. So looks like 4 tiles X 5 Feet=20 tiles.
240 square tiles are needed
647
1120 plus 10% for salvage= roughly1230tiles. you can probably return unused tiles
360 tiles.
Nine square feet is equal to 3.24 20-inch tiles.
20 inches = 1.666 feet 1.66x 1.666 = 2.777 sq feet 78/2.777 = 28 tiles
20" = 2.78 square feet. Now divide the area of the tiles into the area of the room. 140/2.78 = 51 tiles
Two tiles will suffice since they will cover 36 square feet.
There are 4 6X6 tiles per sq foot. So looks like 4 tiles X 5 Feet=20 tiles.
20
7.35 Is what you need
If you mean 20 in x 20 in tiles, the 240 sq ft room is 240 x 144 sq in = 34560 sq in. each tile is 20 x20 = 400 sq in tiles needed are 34560/400 = 86.4 tiles, say 90 tiles