What are the arrangements Socrates suggests for the housing and compensation (pay) of the
guardians and of the auxiliaries? For what reason(s) does he favor such arrangements?
The discussion of the topic of housing and compensation starts at 415d (pp. 94-95 of the Bloom
translation) and continues to the end of Book III. But to answer the second part of this question,
you should look at the context in which this suggestion comes up. Doing this would be the best
way to figure out the reasons for the arrangements.