Kevin plans to put concrete on a rectangular portion of his driveway. The portion is 10 feet long and three inches high. The price of concrete is $98 per cubic yard. The total cost of the concrete Kevin 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?

[1 foot = 12 inches; 1 yard = 3 feet]

a.) 3 feet
b.) 6 feet
c.) 8 feet
d.) 10 feet

Question

Kevin plans to put concrete on a rectangular portion of his driveway. The portion is 10 feet long and three inches high. The price of concrete is $98 per cubic yard. The total cost of the concrete Kevin 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?

[1 foot = 12 inches; 1 yard = 3 feet]

a.) 3 feet
b.) 6 feet
c.) 8 feet
d.) 10 feet

welshfella · Answer

Cost  = volume of concrete needed in cubic yards * 98

72.59 = V * 98

welshfella · Answer

V in cubic yards =  10 * 1/4 * x
                              ----------
                                     3^3

where the width x is in feet

welshfella · Answer

so from  the first equation V = 72.59 / 98 = 0.7407 cu yds

welshfella · Answer

so 
0.7407  =   2.5x
                  -----
                    363

solve for x

welshfella · Answer

* typo in the denominator

0.7407 = 2.5 x
               -----
                 3^3

welshfella · Answer

can you solve that?