Answer: 267 square feet
This value is approximate. The more accurate answer is roughly 266.66667 square feet but even this value is approximate as well.
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Step-by-step explanation:
The scale of 1:40 means 1 inch on paper corresponds to 40 inches in real life. This type of notation is typically found on maps in the bottom corner.
What we'll do is multiply by 40 to go from the measurement on paper to the measurement in real life.
- 6 inches on paper gives 6*40 = 240 inches in real life. Divide by 12 to convert from inches to feet: 240/12 = 20. The room is 20 feet in length.
- 4 inches on paper gives 4*40 = 160 inches in real life. This converts to 160/12 = 13.333 feet roughly, which is the approximate width of the room.
In short,
- 6 inches on paper ---> 20 feet in real life
- 4 inches on paper ---> 13.333 feet in real life (approximate)
From here we multiply the length and width to get the area.
area = length*width
= 20*13.333
= 266.66 which rounds to about 267 square feet.
Feel free to round to some other level of precision. I'm rounding to the nearest square foot because that's the typical precision when it comes to listing sizes of houses and apartments.