If Barbara selects at least one fish for her aquarium, then which one of the following lists the minimum and maximum ...

Branden on January 14, 2021

Not Understanding how to solve this

Hello, I was wondering if you could show me how you are able to solve this efficiently and exactly what the question is asking.

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Shunhe on January 15, 2021

Hi @Branden,

Thanks for the question! This one is definitely worded a bit weird, but it’s asking for something quite simple. What’s the fewest number of different fish Barbara can pick, and the most she can pick? This is going to require knowing the rules you diagrammed out pretty well.

Well, clearly she has to pick at least one fish based on the question stem. But can she pick one, or does she have to pick at least two? Well, sure. For example, she could pick an K. If she picks a K, we’re told she doesn’t pick any Os. And otherwise she doesn’t have to pick anything else. So she could pick just K, which is one species.

Now what’s the most she could pick? Well, we want to include J and L, since those aren’t tied to any other rules. We also want to include O, since no O precludes a lot of other variables based on the rules. Since we pick O, we pick P. Is there anyone else we can pick? Yup, we can pick M or N, but not both. So that means we can pick at most five species, which makes (B) the correct answer.

Hope this helps! Feel free to ask any other questions that you might have.