5. A decision at the margin course. She starts work at 8:00 AM and uses a table to keep track of her progress throughout the day. She notices that as she gets tired, it takes her longer to solve each problem. The marginal, or additional, gain from Eileen's second hour of work, from 9:00 AM to 10:00 AM, is problems. The marginal gain from Eileen's fourth hour of work, from 11:00 AM to noon, is problems. Later, the teaching assistant in Eileen's economics course gives her some advice. "Based on past experience," the teaching assistant says, "working on 50 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? 0 hours working on problems, 4 hours reading 2 hours working on problems, 2 hours reading 3 hours working on problems, 1 hour reading