Answer:
If he kept taking notes at the same pace, he would have 16 pages of notes in his notebook.
Explanation:
By dividing the number of pages of notes taken by the time spent taking them, you can find his rate of note-taking, which is 4 pages an hour. By adding another hour of notes, he should have 16 pages of notes. But if this question is asking for 4 more hours, the answer would be 28 pages.