Hi Joanne,

Eight feet is $8 \times 12 = 96$ inches and 12 feet is $12 \times 12 = 144$ inches. Suppose you start by lying a row of tiles along the long side. Each tile is 20 inches long and

\[\frac{144}{20} = 7.2\]

so you will need 8 tiles, with quite a bit of wastage. Also

\[\frac{96}{20} = 4.8\]

so you will need 5 of these 8 tile long rows to cover the floor. Thus in total you will need $8 \times 5 = 40$ tiles.

If the tiles have a pattern and you need to match them you will probably need more. If you can use the wastage, especially from the long row you may be able to reduce the number of tiles somewhat.

I hope this helps,
Penny