Hi, so i came very close to the "correct answer", i just can't understand why they took certain things into considerations. Ill try to translate the task as best as i can.
You're going to make the foundation and the floor of concrete , the dark blue area is the ground foundation and is 25 cm ( 0.25m ) broad.
A) What is the area of the light blue and dark blue for this figure?
B) In the lightblue area you're going to make a 10CM ( 0,1m) thick concrete layer. The ground foundation shall be 40cm in height (0.4m)
How many cubic meters (m^3 ) of concrete do you need?