Answer: there were 15 tiles in each box
Step-by-step explanation:
Let the number of tiles in each full box be x
Suppose, instead, that Bruce used 6 full boxes of tiles plus an additional 2 tiles. It means that he used a total of
(6x + 2) tiles
Suppose, that Felicia used 5 full boxes of tiles plus an additional 17 tiles. It means that he used a total of
(5x + 2) tiles.
If they each used the same number of tiles, it means that the total number of tiles used by Bruce = total number of tiles used by Felicia. Therefore,
6x + 2 = 5x + 17
6x - 5x = 17 - 2
x = 15
