# Papa is putting new concrete on a driveway. The driveway is 30' x 10' x 9" thick. Concrete is measured by the cubic yard. One sack of dry cement mix costs $7.30, and it takes four sacks to mix up 1 cubic yard of concrete. How much will it cost? ## Papa is putting new concrete on a driveway. The driveway is 30' x 10' x 9" thick. Concrete (a mixture of sand, gravel, and cement) is measured by the cubic yard. One sack of dry cement mix costs$7.30, and it takes four sacks to mix up 1 cubic yard of concrete. How much will it cost Mike to buy the cement?

Assuming you can't buy one third of a sack of cement, it will cost $248.20 #### Explanation: Since we are dealing with cubic yards let's convert our driveway measurements from feet to yards and inches to yards. Remember $36$inches$= 1$yard and $3$feet$= 1$yard So instead of $30$feet $\times$$10$feet $\times$$9$inches We get: $10$yards $\times$$\frac{10}{3}$yards $\times$$\frac{1}{4}$yards Multiplying these together we need: $\frac{25}{3} = 8. \overline{3}$cubic yards If we multiply the amount we need by 4 we get how many sacks of dry cement are required: $\frac{25}{3} \cdot 4 = \frac{100}{3} = 33. \overline{3}$sacks However you probably can't buy one third of a sack so round it up to 34 sacks. Since each sack costs$7.30 we multiply the number of sacks by 7.3:
$34 \cdot 7.3 = 248.2$ which as a cash value equals \$248.20.