If a child is to develop healthy bones, the child's diet must include sufficient calcium. It therefore follows that t...

Skylar on February 9, 2020

@shafieiava, happy to help!

The passage can be diagrammed as follows:
First sentence: HB -> SC
Second sentence: not HB -> not SC
Therefore, the flaw is simply negating the original S->N statement.

Answer choice (B) can be diagrammed as follows:
First sentence: TG -> RAF
Second sentence: not TG -> not RAF
Again, we see the flaw of simply negating the original S->N statement. Since this is the same flaw as is seen in the passage, (B) is correct.

Does that make sense? Please let us know if you have any other questions!

MrLaw on July 11, 2020

Why did you diagram it as not TG -> not RAF vice not RAF -> not TG?

shunhe on July 23, 2020

Hi @Alexander-Blankers,

Thanks for the question! So let’s take a look at what (B) is saying. A cake much contain the right amount of flour in order to taste good. Remember that words like “must,” “need,” etc. generally introduce the necessary condition. And that makes sense, what does this first sentence mean? It means that if a cake tastes good, then it contains the right amount of flour. Because a cake has to contain the right amount of flour to taste good! So we diagram this

TG —> RAF

Now for the second sentence. We’re told that cakes that don’t taste good don’t contain the right amount of flour. Well, how can we rephrase this in if-then language? This is basically saying that if a cake doesn’t taste good, then it doesn’t contain the right amount of flour. So we can diagram this as

~TG —> ~RAF

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