So let’s say we have a width of a hundred inches and each of these tiles is five by five inches. Note that except for the first tile, the others come in pairs. Each pair is ten inches long. So if I take my width, subtract the 5 inches here then I have 95 inches left and how many 10 inch pairs can I put in there? But if divide 95 by 10, that’s 9.5. I discard the remainder, so I know I have nine pairs, and the white one for a total of 19 tiles, 10 white, and 9 red. Great, that’s my answer in this particular instance. Now the next step is to figure it out for arbitrary values after which and the tile sides

pls do it again, this examples is just wrong and therefore confusing

this example sucks

I don't get it why are there only 19 tiles in total. While if the width is 100 inches, and the tiles are 5 inches each. Shouldn't it be 20 tiles in total? Thus there are 10 red tiles and 10 white tiles? 100/5 = 20, yes? no?