Final answer:
The smallest number of pages that the paper could have had is 28.
Step-by-step explanation:
Let's assume the number of pages in the paper is x.
Since Eric writes in sets of four pages and Hermann writes in sets of seven pages, we can set up the following equation:
4n = 7m
Where n is the number of sets of four pages written by Eric and m is the number of sets of seven pages written by Hermann.
In order to find the smallest number of pages, we need to find the smallest values of n and m that satisfy the equation. The smallest possible values for n and m are 7 and 4, respectively.
Therefore, the smallest number of pages that the paper could have had is 4n = 4(7) = 28.