Principle: Anyone who has more than one overdue book out on loan from the library at the same time must be fined if s...

Naz on November 3, 2014

Let's diagram:

Principle: "Anyone who has more than one overdue book out on loan from the library at the same time must be fined if some of the overdue books are not children's books and that person has previously been fined for overdue books."

Under the condition that someone has more than one overdue book out on loan from the library:

not CB & PFOB ==> F
not F ==> CB or not PFOB

To make it valid that Kessler must be fined, some of the books that are overdue out on loan from the library cannot be children's books AND Kessler must have previously been fined for OVERDUE books.

Answer choice (A) states: "Some of the books that Kessler currently has out on loan from the library are not children's books, and Kessler was fined last year for returning a children's book late."

We do not know whether these books that Kessler has out on loan are OVERDUE. They must be overdue to justify the application of the principle.

(B): "One of the overdue books that Kessler currently has out on loan from the library is a novel for adults, and Kessler was fined last year for returning this book late."

Answer choice (B) clearly states that the books are, in fact, overdue, that at least one is not a children's book, and that he was previously fined for this overdue book. Therefore, answer choice (B) justifies the application in the stimulus.

Hope that clears things up! Please let us know if you have any other questions.