Rina is a hard-working college sophomore. One Thursday, she decides to work nonstop until she has answered 132 practice problems for her chemistry 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. Time Total Problems Answered 8:00 AM 0 9:00 AM 60 10:00 AM 96 11:00 AM 120 Noon 132 Use the table to answer the following questions. The marginal, or additional, gain from Rina's second hour of work, from 9:00 AM to 10:00 AM, isproblems. The marginal gain from Rina's fourth hour of work, from 11:00 AM to noon, isproblems. Later, the teaching assistant for Rina's chemistry course gives her some advice. "Based on past experience," the teaching assistant says, "working on 18 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 spend working on problems and how many should she spend reading? 0 hours working on problems, 4 hours reading 1 hour working on problems, 3 hours reading 2 hours working on problems, 2 hours reading 3 hours working on problems, 1 hour reading 4 hours working on problems, 0 hours reading