Passage Summary: At this shop, you can't get a bad review and a raise at the same time. Lester didn't get a raise, so the author assumes he must have gotten a bad review.

Conclusion: Lester must have received a poor performance evaluation.

Reasoning: No employee receives both a poor evaluation and a raise; since Lester did not receive a raise, he must have received a poor evaluation.

Analysis: The flaw here is a failure of formal logic regarding 'exclusive' conditions. The premise states you cannot have both A and B (Not [A and B]). The author then observes 'Not B' and concludes 'A.' This is a mistake because it's possible to have neither A nor B—Lester might have received a great evaluation but still didn't get a raise for other reasons. To parallel this, look for an answer that says two things can't both be true, notes that one isn't true, and concludes the other one must be.