Answer:
The total cost of the rocks needed for the border is $538.80.
Step-by-step explanation:
The length of the lawn is = 150 feet
The width of the lawn is = 80 feet
The gravel border will be 6 feet wide from all sides.
So, bigger rectangle will have length =
feet
And width will be =
feet
Area of the bigger rectangle =
square feet
Area of the smaller rectangle =
square feet
So, area of the gravel area will be =
square feet.
Now depth of gravel is 2 inches. So, volume will be area of gravel times depth.
We will convert 2 inches in feet.
12 inches = 1 feet
So, 2 inches =
feet
cubic feet
1 cubic foot = 0.037037 cubic yard
So, 484.97 cubic feet =
cubic yards
Now cost of gravel per cubic yard is $30.
So, total cost will be =
dollars
Therefore, the total cost of the rocks needed for the border is $538.80.
Please find attached the diagram of the lawn.