How many 10 inch x13 inch tiles 100 square feet?

Answer 1

10" * 13" = 130 sq inches = 130/144 = 0.9028 sq ft.

Area to be covered = 100 square feet so tiles required = 100/0.9028 = 110.77 tiles ie 118 tiles.

That is the mathematical answer. In real life, though, the answer will also depend on how "well behaved" the area to be covered is. If it has lots of awkward corners or curves, you will need to cut more tiles to shape and, unless you are able to use all such offcuts, you will require more tiles.