Bonnie and Bruce have a rectangular swimming pool that is 6 feet wide and 10 feet long. They are going to build a tile border of uniform width around the pool. They have a 105 square feet of tile.

How wide should the border be?

you want the total area, less the pool, to be 105. So, that means that the border has width x, where

(6+2x)(10+2x)-(6)(10) = 105
x = 5/2 ft or 2'6"

To determine the width of the border, we need to subtract the area of the pool from the total area covered by the tiles.

First, let's calculate the area of the pool:
Area of the pool = width × length = 6 feet × 10 feet = 60 square feet

Now, let's subtract the area of the pool from the total area covered by the tiles:
Total area covered by the tiles = 105 square feet

Border area = Total area covered by the tiles - Area of the pool
Border area = 105 square feet - 60 square feet
Border area = 45 square feet

Since the border is uniform in width, we can assume that the width of the border is the same on all sides of the pool. To find the width, we need to divide the border area by the length or width of the pool (since they are the same in this case). Let's use the length:

Width of the border = Border area / Length of the pool
Width of the border = 45 square feet / 10 feet
Width of the border = 4.5 feet

Therefore, the width of the tile border should be 4.5 feet.