This is an exercise in an “Exercises” subdivision at the level of a subsubsection. There is no question other than if the numbering is appropriate. Here is a self-referential link: Exercise 4.2.1.
The subsubsection has no title in the source, so one is provided automatically, and will adjust according to the language of the document.
This solution will migrate to a list of solutions in the backmatter. We include a
sidebyside as a test.
This is a skinny paragraph which should be just 30% of the width.
And another skinny paragraph which should also be just 30% of the width.