Question

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 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

Answer 1

First we need to know the total volume of concrete used:
$V_total = \frac{cost_{total}}{cost{unit}}$
$V_total = \frac{\ 72.98}{\frac{\ 90}{yd^{3}}}$
$V_total = 0.7407yd^{3}$

Now we can use the formula for volume of a rectangular prism:
$V=lwh$
Convert everythig to yards and substitute: 
$0.7407yd^{3}=(3.33yd)(w)(0.08333yd)$
$w=\frac{0.7407}{3.33 \times 0.08333}$
$w \aprox 2.66yd$