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?

Respuesta :

irspow
The volume is:

V=xyz

The cost is:

C=98V

V=C/98

Since V=V we can say:

C/98=xyz  so the missing dimension is:

z=C/(98xy), since C=72.59, x=10ft(yd/3)=10/3 yd, y=3in(yd/36in)=1/12 yd so

z=72.59/(98*10/3*1/12)

z=72.59/(980/36)

z=72.59*36/980

z=2613.24/980 yd

z≈2.67 yd (to nearest hundredth of a yard)

z≈8.00 ft (to nearest hundredth of a foot)