Answer: There are 400 white tiles which Ron will need.
Explanation:
Since we have given that
Number of rows to cover the counter = 8
Number of tiles to cover each 8 rows = 54 square tiles
So, total number of tiles to cover 8 rows is given by

Number of groups on which 4 blue tiles are placed = 8
Total number of blue tiles on 8 groups is given by

Remaining are the white tiles so, it is given by

So, there are 400 white tiles which Ron will need.