i need to know the width of the walkway around the garden
The perimeter of the garden is 180 feet. The length is 50 and the width is 40. You have 784 square foot tiles for a walkway around the perimeter.
You will need 184 tiles to go around the perimeter one time, because you must extend the length by one tile on each end of the lengths so that all the tiles for will butt up against each other (52+52+40+40=184). You now have a walkway that is one tile deep, with 600 tiles left.
Since you have 600 tiles left over, you can keep adding to the width of the walkway. Let's add another layer of tiles all the way around, using up 192 tiles. We had to add another tile to each end of the new length (52+2=54) plus a tile at each end of the length “going up” to get us up and over to the next row (54+2=56) for a total of 192 tiles (56+56+40+40=192). We now have a double tiled walkway, with 408 tiles left over.
Adding a third layer of 200 tiles leaves us with 208 tiles. We had to add a tile at each end of the new length (56+2=58), plus a tile at each end of the length “going up” to get us up and over to the next row (58+2=60) for a total of 200 tiles (60+60+40+40=200).
We can add a fourth layer of tiles in the same manner (64+64+40+40=208), using up our remaining 208 tiles, with none left over.
So, we were able to build a 4 foot walkway around our garden using all of the 784 tiles.