Q24 - Plant species differ in that

[skapur777]

My explanation was that:

Day Length trigger growth
Temp triggers growth

~Day Length so it has to be growth in response to temperature.

I don't see how that follows though considering they are both necessary conditions?

I could match it up to answer choice C but I didn't see how one diagrams D nor how E is incorrect.

[theaether]

I just took this PT this past week actually. I'm going to try to explain a little bit just to help out my own thought processes.

For the argument, it says that growth is triggered by day length, or temperature, or ELSE by a combination of both. That is, it MUST be day length (let's say A), temperature (B), or a combo of those (A and B).

The argument rules out A, and concludes that B must be involved either by itself or with some other factor. This is valid, according to the premise. One trap I personally fall into is "arguing with the premises." I would think, wait but soil can affect renewed growth too! And that is independent of either day length and temperature. But actually, we just have to go with what the premise lays out for us. That it must be A, B, or A+B.

An example argument:
Getting rich can be attributed to personally making money or by getting money from someone, or else by a combination of both. Here, the premises are already establishing that there does not exist a situation where you can get rich without something to do with either making money, or getting money. If I know that a person is rich but didn't make the money himself, then I can safely infer that one factor of how he got rich was that he got it from someone else. Because the premises stipulate this.

(D) The beginning structure is similar, in that it's laying out 3 conditions that apply to every situation, although there is a slight difference in adding the "Three store detectives" condition as well as the fact that there is a numerical quality to the relationship between the 3 conditions. But the conclusion it makes does not use the same reasoning. It does not eliminate the situations of 1 store detective and 2 store detectives and make an inference from that.

(E) This argument had me going for a while when I was taking this PT. The problem with it is that it doesn't limit the factors contributing to how likely the call is to be heard. I can say that a call is more likely to be heard if it's said in English, or if involves saying "Fire!" in a public place, etc. So now, if a call is unheard at maximum loudness, we don't know that we should increase the pitch. Why not just change the message to something the listeners would more easily understand? Invalid deduction.

There's probably even more obvious gaps in why (D) and (E) are wrong, but those are just the ones I quickly spotted. If you look at (C), the language of "some do this, some do that, and ALL OTHERS do both" is very very attractive. It accounts for all possible situations, just like the original argument!

[skapur777]

Brilliant!! Thank you so much!

[bbirdwell]

I agree!

This argument can be boiled down to something nice and simple:
renewed growth --> A or B or both
Therefore:
if renewed growth --> ~A,
we know that renewed growth --> (at least partly) B

Even more simple:
A or B or both
not A, at least some B

(A) A or B; not B, mostly A
not quite a match!

(B) A --> 1, B --> 2; 1, so A.
nope!

(C) A or B or both; not A, B at least helps
great match!

(D) A or B or C... already a bad match.

(E) A rather than B, C rather than D, especially if A and B... already a bad match.

[PhoebeL747]

I agree!

This argument can be boiled down to something nice and simple:
renewed growth --> A or B or both
Therefore:
if renewed growth --> ~A,
we know that renewed growth --> (at least partly) B

I have a question..
Growth can be triggered by A or B or both, shouldn't it be diagrammed as "A or B or both--->Growth" rather than "Growth---> A or B or both" ?

[LeonC641]

I picked the correct answer but, just for the purpose of learning, I wanna discuss further the logical structure of (D). I have some questions regarding the first sentence:

1. Does "either one or two or three" mean to exhaust every and the only scenarios?
2. Is "Depend on" an indicator for either a causation argument or a conditional statement?

Any help will be greatly appreciated.

Leon