Felix used a scale factor of 1 inch = 2.5 feet to draw model of his backyard, as shown below. He is planning to build a fence around the yard. If the cost of the fence is $3.50 per foot, how much will it cost him to build the fence?
Length 2.75in. width 1.25in
Is my answer right? If not, what am I missing?
1.25 X 2.5= 6.875
1.25 x 2.5= 3.125
10.000
10x3.50= $35.00
I wonder why whoever made up this problem didn't use more realistic numbers.
Anyway --
the perimeter is
P = 2(6.875) + 2(3.125)
P = 13.75 + 6.25
P = 20 feet
20 * 3.5 = $70
The numbers are right. I just double checked.
It is a picture of a square. So maybe I should double the numbers since I need to account for the other 2 sides. 10x2=20
20x$3.50 = $70.00 Is this right?
Thank you!
You're welcome.
Your calculations are almost correct, but there is a slight mistake when converting the width of the backyard model from inches to feet.
The length of 2.75 inches stays the same because the conversion factor of 1 inch = 2.5 feet applies to both length and width.
However, the width of 1.25 inches needs to be multiplied by the scale factor of 1 inch = 2.5 feet:
1.25 inches x 2.5 feet/inch = 3.125 feet
Now that we have the correct dimensions, we can calculate the amount it will cost to build the fence. Given that the cost of the fence is $3.50 per foot:
Length: 2.75 inches = 2.75 inches x 2.5 feet/inch = 6.875 feet
Width: 1.25 inches = 1.25 inches x 2.5 feet/inch = 3.125 feet
To find the perimeter (P) of the backyard (which will be equivalent to the amount of fence needed), we use the formula:
P = 2 * (Length + Width)
P = 2 * (6.875 feet + 3.125 feet)
P = 2 * 10 feet
P = 20 feet
Therefore, it will cost Felix $3.50 per foot x 20 feet = $70 to build the fence.
2.75 * 2.5 = 6.875 feet
1.25 * 2.5 = 3.125 feet
That's a pretty small yard -- about the size of a long twin bed mattress.
Are you sure about these numbers?