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But in most cases, that’s not true. When this does happen, the professor may actually be testing the student’s ability to apply concepts to new situations. There is an orgo professor at my school who is notorious for doing that. It’s super frustrating for the students, but that one killer problem actually has very little impact on the grade, since everyone gets it wrong.</p>
<p>I can see how the OP found this situation to be frustrating, and I do agree that what the professor said was misleading. I wouldn’t call it lying because that implies a malicious intent, which I doubt was the case (maybe he changed his mind because he thought he didn’t explain the mechanisms well enough or something). In the future, I think the OP should remain skeptical of such “guarantees.”</p>
<p>OP, you’re probably not the only one in your class who found this to be frustrating. I’m sure someone will bring it up with the professor, who will hopefully realize his mistake. I think professors should just avoid talking about the specifics of exam content, since it satisfies no one, and people often mishear/misinterpret things.</p>