Answer:
Correct answer is B. 5Rolls
Step-by-step explanation:
- First you have to put all values in same unit of measurement,
- knowing that 1 foot=12 inches, we apply 3 rule:
12 inches is 1 feet
6 inches is 6/12 feet= 0,5 feet.
12 inches is 1 foot
30 inches is 30/12 feet=2,5feet.
2. Second,you have to calculate the total surface where you will wallpaper.
So you have to calculate the dimension of 2 different rectangles and substract the surfaces that you don't have to wallppaper (door and windows).
- Let's calculate the surface of the rectancles. Let's put all units in feets.

3. Now we have to calculate the area to substract from the total area, since you will not wallpaper the door and windows:

4. Total area to wallpaper is Total surface of the room minus door and windows surface:

5. Now you have to add 10% waste to the calculated surface:

6. So, you have the real area that will wallpaper considering 10% waste, it is 326.23 square feet. To calculate how many rolls you will need, you have to calculate the surface that each roll covers and then divide total surface by roll surface.


7. As the number of rolls is not integer you have to round, then the answer is you will need 5 rolls of wallpaper.