#25 - If a wig has any handmade components, it is more

[KelseyWoods]

Hi netherlands!

Your diagramming is mostly correct - you only made a small error at the end. From the stimulus, you can't link: m2m ----> HM Foundation.

The premises are:
Handmade Comp ----> More expensive
m2m ----> Med to Exp
HM Foundation ----> Human Hair
Human Hair ----> Dry Clean

As you did, you can combine the last two premises:
HM Foundation ----> Human Hair ----> Dry Clean

The conclusion is:
m2m ----> Dry Clean

We are asked to justify that conclusion and to do so, we need to link m2m onto our HM Foundation ----> Human Hair ----> Dry Clean chain.

Answer choice A says:
Med to Exp ----> HM Foundation

If we add A to our premises, it builds the link between m2m and Dry Clean that we need to prove our conclusion (we end up not needing the very first premise (Handmade Comp ----> more expensive) to prove our conclusion):

m2m ----> Med to Exp (Premise)
Med to Exp ----> HM Foundation (Answer Choice)
+ HM Foundation ----> Human Hair ----> Dry Clean (Premise)
---------------------------------------------------------------
m2m ----> Med to Exp ----> HM Foundation ----> Human Hair ----> Dry Clean

Take out the middlemen and you have:
m2m ----> Dry Clean (Conclusion)

Let us know if this is still confusing!

Kelsey

[netherlands]

Ok that makes sense! Whenever I'm connecting separate chains:

Premise: A C
So, A G
Premise: E F G

I get confused about if I just add the entire:

(A C) chain onto the (E F G) chain.

Or if I just add the A E F G and omit the C.

But I'm seeing now that it's mainly in order of presentation and reading the answer choices to see which works obv helps too!

[cd1010]

Hi! I have a lot of trouble with double negatives, and under time pressure, I could not parse out this sentence: "Handmade foundations are never found on wigs that do not use human hair."

Is there a more intuitive way or mechanistic way to think about how to diagram this? Thanks!

[Chandler H]

Hi! I have a lot of trouble with double negatives, and under time pressure, I could not parse out this sentence: "Handmade foundations are never found on wigs that do not use human hair."

Is there a more intuitive way or mechanistic way to think about how to diagram this? Thanks!

Hi cd1010,

I don't blame you! This is a complex sentence. In this case, it may be easier to diagram it if you switch around the clauses, as in:

If a wig does not use human hair, it does not have a handmade foundation.

That would give you this diagram, and the contrapositive, which is much more helpful:

HH HF
HF HH

That is, if a wig has a handmade foundation, it uses human hair.

Does that make sense?