Answer:
Actual length of wall = 30ft
Step-by-step explanation:
We have scale of a room as 3 inch for 5ft.
We can write scaling factor as:
Scaling factor = 3 /60 (Since 5ft = 60 inches )
Scaling factor = 1/20
Now,
a wall in the blueprint is 18inch.
So actual length of wall can be determined by dividing 18 inch by the scale factor.
i.e actual length of wall = 18 / scale factor = 18 / (1/20)
actual length of wall = 18* 20 = 360 inch = 30ft (Since 360 inch = 30ft)
Hence Actual length of wall = 30ft
