Logical Reasoning: Problem Set #1, #38

[Nel]

Hello.

I am struggling with Conditional Reasoning Must Be True problems that involves modifiers, such as "most", "some", "few", "no", etc. Maybe my struggle is caused by double arrow as well.

Below is the specific problems that I do not understand.


2) SUPPLEMENTAL PROBLEM SETS, Logical Reasoning: Problem Set #1, #38

Could anybody explain why the right answers are right?



2) SUPPLEMENTAL PROBLEM SETS, Logical Reasoning: Problem Set #1, #38

generous parents (Gen) Good parents (GP)

self centered parents (SC) GP
　　　　　　　　　　　　(some)
GP good listner (GL)

The answer (MBT) was "Some GL are SC"

I think my problem with this question is just same as the one with 1).
How come GL can be left side of the arrow?
GL SC
　(some)

I hope someone can point out my problem/misunderstanding.
Thank you very much for your time, in advance.

[Dave Killoran]

Hi Nel,

Thanks for the question, but they both seem to reference #38? I'll address the one you describe in detail, and if you have a question about a different problem in that set, if you could, please post it in a different thread.

When you have this chain of connections:

self centered parents (SC) GP good listener (GL)

You are able to draw the inference that SC GL.

But, "some" is a reversible term, and so it can be read both ways, meaning that GL SC is also true.

When terms like "some" and "most" are added to conditional reasoning, it turns into what we call Formal Logic. Have you had a chance to check out the information online about Formal Logic? If not, it might help you nail these kinds of problems

Thanks!

[Nel]

Hello Dave.
Thank you very much for the explanation.

I did not know about online Formal Logic section. I will definitely review the section as I have been constantly making a wrong choice for this type of question.

Again, thank you.

[Dave Killoran]

Great, glad I could help! There's quite a bit of info there, and I'm sure it will clear all of this up for you. If not, definitely ask us question about it.

Thanks!