Concrete is often used to surface roads. Concrete is mostly a mixture of water, rocks or aggregate, and a powdery substance of calcined lime (also called cement). To create a strong, durable concrete, the proportion of the ingredients is important. A mixture that does not have enough cement paste will be difficult to distribute and will produce rough surfaces. A mixture with too much cement paste will result in a smooth surface, but resulting concrete can easily crack.

The table shows a concrete mixture used to pave 50 yards of street. Fill in the amount of each ingredient needed to pave 300 yards of street.