Answer:
8
Step-by-step explanation:
Let's first measure the four walls. We'll have 2 walls 48 ft wide x 18 ft high (the longer walls), then 2 walls 36 ft x 18 ft high.
These are rectangles we can easily calculate the area:
longer walls: 2 (48 * 18) = 2 * 864 = 1,728 sq ft
shorter walls: 2 (36 x 18) = 2 * 648 = 1,296 sq ft
Total of the walls: 1,728 + 1,296 = 3,024 sq ft.
Now, we assume they'll paint everything and that there are no windows.
Each can covers 400 sq ft.
If we divide 3,024 by 400 we get 7.56
So, they'll need to buy 8 cans of paint to do the job. In such problems, we always round up, otherwise they wouldn't have enough paint.
