Beth is a hard-working college freshman. one thursday, she decides to work nonstop until she has answered 200 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 80
10: 00 am 140
11: 00 am 180
noon 200

use the table to answer the following questions.

the marginal, or additional, gain from bethâs second hour of work, from 9: 00 am to 10: 00 am, isproblems.

the marginal gain from bethâs fourth hour of work, from 11: 00 am to noon, isproblems.

later, the teaching assistant in bethâs chemistry course gives her some advice. "based on past experience," the teaching assistant says, "working on 50 problems raises a studentâs 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?

a. 1 hour working on problems, 3 hours reading
b. 2 hours working on problems, 2 hours reading
c. 3 hours working on problems, 1 hour reading
d. 4 hours working on problems, 0 hours reading