Some exam booklets might have rules that notes should only be written on the outside and inside covers - as in the following example.

"For rough work unruled pages are provided on the cover of the book. If you require more than these, use a ruled page but cross the rough work through before handing the book in."

If the rules allow it, write your answers only on right-hand pages.

Leave left-hand pages blank for notes, corrections, or later additions.