Later, the teaching assistant in Yvette’s economics course gives her some advice. "Based on past experience," the teaching assistant says, "working on 30 problems raises a student’s exam score by about the same amount as reading the textbook for 1 hour." For simplicity, assume students always cover the same number of pages during each hour they spend reading. Given this information, in order to use her 4 hours of study time to get the best exam score possible, how many hours should she have spent working on problems, and how many should she have spent reading?