A) Diagram
Below is a sketch of the recctangular lawn (the inside rectangle) and the gravel border.
6 ft + 150 yards + 6 ft
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| |
| --------------------- |
| | | |
| | | | 6 ft + 80 yard + 6 ft
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| --------------------- |
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|------------------------------|
B) How many square feet of the gravel will surround the lawn?
Conversion: 1 yard = 3 feet
=> 80 yard = 80*3 feet = 240 feet
=> 150 yard = 150 * 3 feet = 450 feet
Area of the external rectangle = (6 ft + 240 ft + 6 ft) (6 ft + 450 ft + 6 ft) = 252 ft * 462 ft = 116,424 ft^2
Area of the internal rectangle = 240 ft * 450 ft = 108,000 ft^2
Area of the gravel border = 116,424 ft^2 - 108,000 ft^2 = 8424 ft^2
answer: 8424 ft^2
C) volume
volume = area of the base * depth
2 inches = 2/12 ft = 1/6 ft
=> volume = 8424 ft^2 * 1/6 ft = 1404 ft^3
answer: 1404 ft^3
C) cost
1 yard^3 = $ 30
1yard ^3 = (3 feet)^3 = 27 ft^3
=> cost = $ 30 / 27 ft^3
=> 1404 ft^3 * $30 / 27 ft^3 = $ 1560
answer: $ 1560
