Alright, here is my problem:

30 buses are to be used to transport 2000 refugees from Location A to Location B. Each bus has 80 seats. Assume one seat per passenger. Prove that one of the buses will have at least 14 empty seats.

Now.. $\displaystyle \frac{2000}{80}=25$ which means we wont need to use the 30 buses or.. we will have a certain amount of people in each bus to use all of the buses. But.. where do I go from here? Any help would be appreciated!