Paul plans to put concrete on a rectangular portion of his driveway. The portion is 12 feet long and 6 inches high. The price of concrete is $98 per cubic yard. The total cost of the concrete Paul needs is $108.89. Which of the following is closest to the width of the portion of the driveway on which Paul plans to put concrete?
[1 foot = 12inches; 1 yard = 3 feet]
3 feet
5 feet
8 feet
10 feet
We need to set this up as an algebra problem.
But before we do that, we need to make sure all our numbers are in the same base, so well convert all the numbers to yards, becuase that's what they sell the concrete in.
12 feet = 4 yards
6 inches = 1/6 yards
And we know that width*length*height @ $98 per yard = 108.89
So width*length*height*98=108.89
We don't know the width, so let's call this "x"
x*4*1/6*98=108.89
x*4/6*98=108.89
x*392/6=108.89
x*65.3333=108.89 ---Divide both sides by 65.3333
x = 1.66666
x = 1 and 2/3 yards ---Change to feet by multiplying the right side by 3
x = 5 feet
So the width of the driveway is 5 feet.
We need to set this up as an algebra problem.
But before we do that, we need to make sure all our numbers are in the same base, so well convert all the numbers to yards, becuase that's what they sell the concrete in.
12 feet = 4 yards
6 inches = 1/6 yards
And we know that width*length*height @ $98 per yard = 108.89
So width*length*height*98=108.89
We don't know the width, so let's call this "x"
x*4*1/6*98=108.89
x*4/6*98=108.89
x*392/6=108.89
x*65.3333=108.89 ---Divide both sides by 65.3333
x = 1.66666
x = 1 and 2/3 yards ---Change to feet by multiplying the right side by 3
x = 5 feet
So the width of the driveway is 5 feet.