Kevin plans to put concrete on a rectangular portion of his driveway. The portion is 10 feet long and 3 inches high. The price of concrete is $98 per cubic yard. The total cost of the concrete Keven needs is $72.59. Which of the following is closest to the width of the portion of the driveway on which Kevin plans to put concrete?
3 feet
6 feet
8 feet
10 feet
We know: l = 10 ft h = 3 in = 3 * 0.083 ft = 0.25 ft w = ? The volume of a rectangular concrete is: V = l * w * h V = 10 ft * w * 0.25 ft V = 2.5w ft²
The price is $98 per cubic yard: $98/1yd³ = $98/27ft³ = $3.63/ft³
The price is $3.63 per cubic feet. The total cost of the concrete Keven needs is $72.59: V * $3.63 = $72.59 2.5w * 3.63 = 72.59 9.075w = 72.59 w = 72.59 / 9.075 w = 7.99 ≈ 8 ft
