1. "Let me look into that and get you an answer in a couple days." This says the person doesn't know, will work on finding out, and will provide an answer. The person received a request and has taken it upon themselves to do their job.
2. "I think that presentation from a meeting last month mentioned it." This is a guess. This person doesn't know, and they don't know that they don't know. They didn't give me the file they were talking about, or even send me a link to it. This person thinks they answered a question but in fact have done absolutely nothing.
If you're gonna answer a question, at least answer the damn question. Don't say something and act like your job is done.