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Sufficient & Necessary Questions - - Question 31

The chances that tropical storms will develop in a given area increase whenever the temperature of a large body of wa...

zacharylouiskane@gmail.com April 23, 2020

Where Do I begin to make the chain

I don't know if others are having the same trouble as me in this area but here goes my question..... In regards to taking a set of facts or an argument and creating longer chains.... Where do we start? I feel sometimes I am cherry picking.... are we intending to take one piece of logic from each premise and principal?

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shunhe May 2, 2020

Hi @zacharylouiskane@gmail.com,

Thanks for the question! It’s definitely something you have to get used to. So let’s say we have a set of facts or an argument, or the stimulus. Where do we start? Quite simply, we read through the stimulus, and we diagram sentences that we might think are useful. And it is important to cherry pick, since not everything will be relevant to the logic of the stimulus. Let’s take this question you commented on as an example.

We’re told first that there’s a higher chance that tropical storms will develop whenever (“if”) the temperature of a large body of water in the area exceeds 26 degrees Celsius to a depth of about 60 meters. Seems like this could be useful, so let’s diagram it.

Large >26 degrees 60 meter water —> Higher chance tropical storm

Ok, now the next statement is a straight up if statement, so we can diagram it as well. It tells us that if atmospheric CO2 continues to increase, then there’s going to be a rise of the temperature of all water, and so there’s going to be more of those kinds of large bodies of water. So

carbon dioxide increase —> all water temperature rise —> more large >26 degrees 60 meter water

Now, notice that the “more large >26 degrees 60 meter water” appears in both the statements we diagrammed, so we are probably going to have to link them together. And we can also get rid of the “all water temperature rise” as superfluous since it doesn’t really show up in the answer choices or in any of the other logic statements. So we have

CO2 increase —> More large >26 degrees 60 meter water
Large >26 degrees 60 meter water —> higher chance tropical storm

And putting these together, we know that CO2 increases will lead to a higher chance of tropical storms, which is what the correct answer, (A), tells us. So generally, each “premise” will provide a piece of logical information, yes. Though that doesn’t mean each sentence will; sometimes, a sentence can have more than one premise in it. Just get everything down first and see how you can link things together. This is the key to making logical chains.

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

shunhe May 2, 2020

Hi @zacharylouiskane@gmail.com,

Thanks for the question! It’s definitely something you have to get used to. So let’s say we have a set of facts or an argument, or the stimulus. Where do we start? Quite simply, we read through the stimulus, and we diagram sentences that we might think are useful. And it is important to cherry pick, since not everything will be relevant to the logic of the stimulus. Let’s take this question you commented on as an example.

We’re told first that there’s a higher chance that tropical storms will develop whenever (“if”) the temperature of a large body of water in the area exceeds 26 degrees Celsius to a depth of about 60 meters. Seems like this could be useful, so let’s diagram it.

Large >26 degrees 60 meter water —> Higher chance tropical storm

Ok, now the next statement is a straight up if statement, so we can diagram it as well. It tells us that if atmospheric CO2 continues to increase, then there’s going to be a rise of the temperature of all water, and so there’s going to be more of those kinds of large bodies of water. So

carbon dioxide increase —> all water temperature rise —> more large >26 degrees 60 meter water

Now, notice that the “more large >26 degrees 60 meter water” appears in both the statements we diagrammed, so we are probably going to have to link them together. And we can also get rid of the “all water temperature rise” as superfluous since it doesn’t really show up in the answer choices or in any of the other logic statements. So we have

CO2 increase —> More large >26 degrees 60 meter water
Large >26 degrees 60 meter water —> higher chance tropical storm

And putting these together, we know that CO2 increases will lead to a higher chance of tropical storms, which is what the correct answer, (A), tells us. So generally, each “premise” will provide a piece of logical information, yes. Though that doesn’t mean each sentence will; sometimes, a sentence can have more than one premise in it. Just get everything down first and see how you can link things together. This is the key to making logical chains.

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

zacharylouiskane@gmail.com May 5, 2020

Understood, also in regards to knowing when to utilize the contrapositive. They were not needed in a question such as this one but how do we know when we need to link lets say as an example the third "original" premise and the contrapositive of the first premise. I guess this is a two part inquiry... 1.How do we know when we need to utilize the contrapositive of a statement and when its needed in others words to immediately be written underneath.

2. Is it safe to assume for instance we had a diagram and for 2/3 of the diagram sentences we see something with the same variable is it safe to assume these will be able to be combined and the other sentence without a common variable is just on its own?