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

Additional information:

Dina's marginal gain for working on problems is 100 problems during the first hour, and 75 problems for the rest of the hours. Gin's gains for reading one hour is equivalent to 87.5 problems.

B) 1 hour working on problems, 3 hours reading

Explanation:

Dina has to make her decision based on her marginal gain.

marginal gain for working on problems          marginal gains for reading

100 for the first hour                                          87.5 for the first hour

75 for the second hour                                     87.5 for the second hour

75 for the third hour                                          87.5 for the third hour

75 for the fourth hour                                        87.5 for the fourth hour

Dina's marginal gain for working on problems is larger for the first hour only, then the marginal gain for reading is larger. Therefore Gina should only work on problems for one hour and read for the other three.