Answer :
Given:
Lucy decides to paint only the walls of 3 bedrooms in her house.
Each room is 14 feet by 12 feet with 8-foot ceilings.
Each door has dimensions of 6.5 feet by 2.5 feet.
Each window has dimensions of 4.5 feet by 3 feet.
1 gallon of paint will cover 350 square feet.
Paint is sold in 1-gallon containers.
Required:
We need to find the minimum number of 1-gallon containers needed for paint.
Explanation:
The surface area of the walls of the rooms is
[tex]SA=(14\times8\times2)+(12\times8\times2)[/tex][tex]SA=416\text{ ft}^2[/tex]Since you dont paint doors and windows, you subtract the surface area of them.
The doors have a surface area of
[tex]6.5\times2.5=16.25\text{ ft}^2[/tex]The window has a surface area of
[tex]4.5\times3=13.5\text{ ft}^2[/tex][tex]W\text{ need to paint 416-\lparen16.25+13.5\rparen= 370 ft}^2.[/tex][tex]\text{ Since there are 3 rooms you multiply this by 3 to get 3}\times370\text{ ft}^2=1110\text{ ft}^2.[/tex]Divide 1110 by 350 since 1 gallon of paint will cover 350 square feet.
[tex]\frac{1110}{350}=3.1714\text{ gallon}[/tex]Since you cannot get part of a gallon you need 4 gallons.
Final answer:
4 gallons need to paint.