Answer:
11.2 gallons.
Step-by-step explanation:
We have been given that a rectangular prism-shaped room is 18 ft by 10 ft and 8 ft high. We are asked to find the gallons of paint needed to paint the walls of room.
First of all, we will find area of walls, we need to paint.
2 walls would be [tex]18\text{ ft}\times 8\text{ ft}[/tex]
2 walls would be [tex]10\text{ ft}\times 8\text{ ft}[/tex]
[tex]\text{Total area of walls}=2(18\text{ ft}\times 8\text{ ft}+10\text{ ft}\times 8\text{ ft})[/tex]
[tex]\text{Total area of walls}=2(144\text{ ft}^2+80\text{ ft}^2)[/tex]
[tex]\text{Total area of walls}=2(224\text{ ft}^2)[/tex]
[tex]\text{Total area of walls}=448\text{ ft}^2[/tex]
We have been given that 1 gallon of paint covers 40 sq ft. To find the gallons of paint needed, we will divide total area by 40.
[tex]\text{Gallons of paint needed}=\frac{448}{40}[/tex]
[tex]\text{Gallons of paint needed}=11.2[/tex]
Therefore, 11.2 gallons of paint are needed to paint the walls.