Ingrid needs to paint her bedroom walls. The room is 9 ft tall by 12 ft wide and 11 ft long. It has a door that is 7 ft tall by 3.5 ft wide and two windows 3.5 it by 3.5 ft that don't need paint.

Question

How many gallons of paint should Ingrid buy if 1 gallon covers 102 square ft?

Answer 1

To start, we need to calculate the total area of the walls that need to be painted. Since we know the dimensions of the room, we can calculate the area of each wall and then add them together.

The ceiling is not included in this calculation, as it does not need to be painted.

First, let's calculate the area of the two longer walls:
Length of the longer walls: 11 ft
Height of the longer walls (excluding the area covered by the door): 9 ft - 7 ft = 2 ft
Therefore, the area of each longer wall is 11 ft * 2 ft = <<11*2=22>>22 square ft.

Next, let's calculate the area of the two shorter walls:
Length of the shorter walls: 12 ft
Height of the shorter walls (excluding the area covered by the door): 9 ft - 7 ft = 2 ft
Therefore, the area of each shorter wall is 12 ft * 2 ft = <<12*2=24>>24 square ft.

Now, let's calculate the area of the door:
Height of the door: 7 ft
Width of the door: 3.5 ft
Therefore, the area of the door is 7 ft * 3.5 ft = <<7*3.5=24.5>>24.5 square ft.

After that, we need to subtract the area of the door from the total area of the longer walls:
Total area of longer walls: 2 * 22 square ft = 44 square ft
Total area of longer walls excluding the area covered by the door: 44 square ft - 24.5 square ft = 19.5 square ft.

Lastly, we can calculate the total area of all the walls that need to be painted by adding the area of the shorter walls, the area of the door, and the total area of the longer walls excluding the area covered by the door:
Total area of all walls that need to be painted: 2 * (24 square ft) + 24.5 square ft + 19.5 square ft = 91 square ft.

Now, we need to calculate how many gallons of paint Ingrid should buy. We know that 1 gallon of paint covers 102 square ft:

Number of gallons of paint needed: 91 square ft / 102 square ft/gallon ≈ 0.8922 gallons.

Therefore, Ingrid should buy approximately 0.8922 gallons of paint.