The floor is 80 decimeters long and 60 decimeters wide. From the point of view of never wasting materials, you can choose the square floor tile with the side length of how many decimeters? It is more appropriate to choose the floor tile with the side length of how many decimeters? Tell me your reasons

The floor is 80 decimeters long and 60 decimeters wide. From the point of view of never wasting materials, you can choose the square floor tile with the side length of how many decimeters? It is more appropriate to choose the floor tile with the side length of how many decimeters? Tell me your reasons

Do you think this question is on the matching? I'm doing it right now. Is it predestined?