Well, I am sure glad I sent my teacher the question as well, I didn’t just settle for the class mates answer. My interpretation of the question was right, that means I do need the other book. I understood it must be something in the other book, but my class mates answer was logical, but I had interpret it differently. I should have trusted my gut feeling. Well. I need to write down the answer right. I have to get the book. I got a reply from the teacher answering my question what the question asked about.