Alandscaper has 125 times to build a square patio the patio must have an area of at least 80 ft.² hey. what are the possible arrangements for the patio b. how many tiles are not using each arrangement

QA. 
Assuming the dimensions have to be in exact feet then you could have 
9ft *9ft = 81square feet 
10 ft * 10 ft = 100 square feet 
11 ft * 11 ft = 121 square feet. 

QB. 
If each tile is 1 ft * 1 ft ie 1 square foot 
Then 
9' * 9' would mean 125 - 81 = 44 tiles would not be used 
10' * 10' = 125 - 100 = 25 tiles not used 
11' * 11' = 125 - 121 = 4 tiles not used 

There is 240 red cars and there is 400 blue cars because 240/3=80 and 80*5=400