Final answer:
Eric will have to spend 17 hours in class before he will have a total of 22 pages of notes in his notebook.
Step-by-step explanation:
To find the number of hours Eric will have to spend in class before he has a total of 22 pages of notes, we need to calculate how many pages he will take during classes. He has already taken 5 pages on his own, so he needs to take 22 - 5 = 17 pages during class.
Since he takes 1 page during each hour of class, he will need to spend 17 hours in class to have a total of 22 pages of notes in his notebook.
Therefore, the correct answer is C. 17 hours.