The formula to calculate the Cost Per Yard (CPY) is:
\[ CPY = \frac{TC}{L/3} \]
Where:
Let's say the total cost (TC) is $300 and the length (L) is 90 feet. Using the formula:
\[ CPY = \frac{300}{90/3} \]
We get:
\[ CPY = \frac{300}{30} = 10 \text{ $/yard} \]
So, the cost per yard is $10 per yard.