In the floor of a particular kitchen owned by an abstract artist, each row of tiles to the right of the first row contains two fewer tiles than the row directly to its left. If there are nine rows in all and a total of 504 tiles in the floor, how many tiles does the leftmost row contain?
The middle row of the 9 contains the average number of tiles, 504/9 = 56. The row that is 4 to the left of that contains 4×2=8 more tiles, so contains ...
