Hi, could you please tell me how to do question number 9? I understand how to find the surface area of question 8 but question 9 really confuses me. Thanks so much!

Answer:
3.6 liters
Step-by-step explanation:
So the ceiling an the walls, you are covering 5/6 surfaces.
Front 4.2*2.5= 10.5
Side 4*2.5=10
1 Top 4.2*4= 8.4
All together =28.9 M /8= 3.6 liters of paint would be needed