First we should find the total volume of the dirt that must be evacuated:
![30yd*15yd*3yd=1350yd^(3)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/lzyub4mteq0uvrvbwrr9kftt8l4yxmtpra.png)
Then we are told that the truck's capacity is 3 cubic yards. So then we must divide this total amount of dirt that must be evacuated and divide by 3 (the hauling capacity of the truck):
![(1350yd^(3))/(3yd^(3))=450](https://img.qammunity.org/2019/formulas/mathematics/middle-school/xjluv7dvvitwgjfoqh4c5jcin1j8afnlnc.png)
So now we know that it will take 450 trips to complete the dirt evacuation.