We know that a street cleaning crew works Monday to Friday. It takes them an entire morning or an entire afternoon to clean a street. The crew cleaned exactly eight streets in one week.
Rules 1 and 2 tell us that the crew did not clean any street on Friday morning or Wednesday afternoon.
We also learn from Rules 3 and 4 that the crew cleaned Fourth Street on Tuesday morning and it cleaned Seventh Street on Thursday morning.
_ 4 _ 7 X _ _ X _ _ M T W R F
Rule 5 tells us that the crew cleaned Fourth Street before Sixth Street and after Eighth Street.
8 > 4 > 6
Rule 6 tells us that the crew cleaned Second, Fifth, and Eighth streets on afternoons.
Since Eighth Street must be cleaned before Fourth Street and must be cleaned on an afternoon, Eighth Street must have been cleaned Monday afternoon.
_ 4 _ 7 X 8 _ X _ _ M T W R F
The question stem tells us that the crew cleaned Second Street earlier in the week than Seventh Street. The three remaining slots we have open prior to Seventh Street are Monday and Wednesday morning and Tuesday afternoon. Rule 6 tells us that Second Street was cleaned on an afternoon; therefore, Second Street must have been cleaned on Tuesday afternoon.
Therefore, while there is no explicit rule precluding Fifth Street from being cleaned on Tuesday afternoon, the conditions and the question stem require that Second Street is cleaned on Tuesday afternoon.
Hope this helps! Please let us know if you have any further questions.
