Question

Solve this problem. Find the number of gallons of paint needed to cover all four sides four sides) of the building shown with two coats of paint if one gallon covers 350 square feet. Disregard windows and doors. Round to the nearest gallon.

Answer 1

The complete question in the figure attached

1) calculate the area all four sides
A=[12+9+12+9]*8=336 ft²

if 1 gallons---------------------------- > covers 350 ft²
X------------------------------------ > 336 ft²
X=336/350=0.96 gallons
but remember 
that there are two coats of paint
therefore
0.96*2----------- > 1.92------- > 2 gallons

the answer is 2 gallons

Answer 2

Answer: the answer is 3 gallons of paint is required to paint the building.

Step-by-step explanation:

The area to be painted is:

= 2× [Area of Rectangle with dimensions 20 ft.×10 ft.+Area of triangle with height 5 ft. and base 20 ft.+Area of rectangle with dimensions 24 ft. and 10 ft.]

=2×[20×10+(1/2)×5×20+24×10]

=2×[200+50+240]

=2×490

=980 square ft.

Hence, the area to be painted=980 square feet.

Now, amount of paint require to cover 350 square feet=1 gallon.

i.e. 1 square feet requires=1/350 gallon of paint.

⇒ 980 square feet requires=980/350=2.8 gallons of paint.

Hence, to the nearest gallon we could say that:

3 gallons of paint is required to paint the building.