Which one of the following statements most accurately characterizes a difference between the two passages?

Lianne on February 9, 2018

Confused by True v. False questions

I am confused by the true vs false questions. In the video, it seems like you should find the phrase in the chart (not talking about EXCEPT situations) and the correct answer would be the logical equivalent, with incorrect being logical opposites, but some of the correct answers are the phrase in the true v. false chart with the logical opposite of that phrase as the incorrect answer. How can you tell when you need to go to the logical equivalent to determine the answer vs not? And how does that then feed into the EXCEPT questions? Thank you! :)

4 Replies

Mehran on February 10, 2018

@pepperlei would you like to post a question stem from a True v. False drill here that is giving you trouble and we can walk you through it?

Lianne on February 13, 2018

Hi Mehran! Thank you. Most of them gave me trouble, actually. :-/ I will need to review that section of the intro to logical reasoning section. Here are a couple of questions I am having trouble with:

If the statements on which the conclusion above is based are all true, each of the following could not be true EXCEPT:

If all the statements in the passage are true, each of the following must also be true EXCEPT:

Thank you, Mehran!! I know both examples are Except examples, but the non-except ones were giving me trouble too so I think I missed something in my notes.

Mehran on February 14, 2018

@pepperlei okay, both of these are rather straightforward since they are both stated in terms of true already.

Let's start with the second one first:

"If all the statements in the passage are true, each of the following must also be true EXCEPT:"

This is already framed in terms of true so all you need to remember is that we are looking for the logical opposite of "Must Be True" because of the "EXCEPT." Stated another way, the four incorrect answer choices "must be true" whereas the correct answer choice is the logical opposite of "must be true," which is?

Not Necessarily True

Now let's look at the first example:

"If the statements on which the conclusion above is based are all true, each of the following cannot be true EXCEPT:"

I made a subtle adjustment to your example, i.e. "cannot be true" instead of "could not be true."

So again, this is already framed in terms of true so we are looking for the logical opposite of "cannot be true" because of the "EXCEPT." Stated another way, the four incorrect answer choices "cannot be true" whereas the correct answer choice is the logical opposite of "cannot be true," which is?

Could Be True

Now here's one for you to try:

"Each of the following must be false EXCEPT:"

This one is a bit more challenging since it is not already framed in terms of true.

What would be the criterion for the correct answer choice? The incorrect answer choices?

Lianne on February 14, 2018

Hi Mehran!

This is very helpful and it's given me something else to think about when answering these, which I hadn't thought about: is the statement given in terms of false or true.

To clarify,
- how can you determine whether the stem is already stated in terms of true or in terms of false?
- I think I am starting to figure out the idea and whether it has a relationship to the logical equivalent, but would love your thoughts.

So, for the example you've given, the logical equivalent for must be false is: cannot be true. Since it's an except, then would the correct answer be the logical opposite of cannot be true, which is "Could be True?"

I appreciate your help walking through this. :)