Suppose that Piper is a diligent second-year college student. One Sunday, she decides to start the day by working through 150 sample multiple choice problems to study for her computer science class. She starts work at 7:00 AM and uses a table to keep track of her progress throughout the day. She notices that as she the hours pass, it takes her more time to solve the problems.

Time	Total Problems Solved
7:00 AM	0
8:00 AM	60
9:00 AM	105
10:00 AM	135
11:00 AM	150

Use the table to answer the following questions.

The marginal, or additional, gain from Piper's second hour spent working, from 8:00 AM to 9:00 AM, is how many

problems?

The marginal gain from Piper's fourth hour spent working, from 10:00 AM to 11:00 AM, is how many problems?

The following week, Piper's computer science faculty advisor gives her some advice. In all their years of teaching they claim to observe that working on 52.5 multiple choice questions boosts a student's test score by about the same amount as spending an hour reviewing lecture notes. For simplicity, assume students are able to review lecture notes at a constant pace during each hour spent studying.

Given this information, in order to use her 4 hours of time spent studying to get the highest possible test score, how many hours should she have spent solving multiple choice problems, and how many hours should she have spent reviewing lecture notes?

0 hours working on problems, 4 hours reading

1 hour working on problems, 3 hours reading

3 hours working on problems, 1 hour reading

4 hours working on problems, 0 hours reading