Q24 - Any driver involved in an accident

[stellajch]

I was just wondering how the stimulus for this question was written in the conditional form? I have a feeling the conditional form I wrote is wrong but here it is:

PI or PE500 -> RA
~RA -> Incapable
Ted = ~RA

PI = Personal injury
PE500 = property damage exceeding $500
RA = Required to Report accident
Incapable = Incapable of doing so

Thank you!

[ohthatpatrick]

Close, but not quite. This is a really tricky conditional situation.

It's saying
If A, then B, unless C.

Quick topical example:
If Hillary runs, then she'll become President, unless Jeb Bush is the Republican nominee.

The way you handle these is you add the unless "if not" consideration to the trigger.

If H runs and Jeb Bush is NOT the Repub nominee, H will be Pres.

Does that feel right?

We're basically saying, as long as Jeb Bush isn't the nominee, we can safely say "if Hillary runs, she'll be Pres".

So the conditional here would look like
If you're in an accident with personal/property damage $500+
and
you're capable of reporting the accident
then
you're required to report the accident.

Cleaned up:
Damage is $500+ AND Capable --> Req'd

The contrapositive would be
~Req'd --> ~Damage of $500+ OR ~Capable of reporting.

Since they provide us with the fact of "~Req'd", we get to make this INFERENCE:
~Damage of $500 OR ~Capable of reporting

Since at least one of those ideas must be true, I would expect LSAT to potentially give us some conditional that looks like
"If it's not the first thing, it's the second thing"

(A) It might be that he's Incapable AND there was $500+ damage. "OR" means "at least one". This answer choice is acting like it's Thing 1 or Thing 2, but not both.

(B) This looks good. This is the "if thing 1 doesn't apply, then thing 2 must apply".

(C) Where did this "someone else is required" idea come from? We didn't get any rule about that.

(D) We can't make this leap conditionally. Conversationally, there are multiple ways to be incapable of reporting an accident ... injury is one way .... phone is dead / no service is another.

(E) It's possible that people WERE injured and there WAS $500+ property damage. The reason he's not required might just be that he's incapable of reporting.

B is the correct answer

Hope this helps.

[sh854]

I understand the explanation listed above for this question. However, I consistently get these types of questions wrong (where they give a scenario and ask you why the scenario does/does not apply to a person. What are some ways we can tackle this type of question?

[tommywallach]

Nothing magical! Just try to follow the train of logic, as Patrick does here. Feel free to go just to pure logic, or to replace the "words" in the text with something that's easier to follow (like the Clinton/Bush example). Good luck!

-t

[erikwoodward10]

Cleaned up:
Damage is $500+ AND Capable --> Req'd

I used an entirely different approach, and I think it's logical as well. I used the following chain:

~incapable --> REQUIRED REPORT for accident personal injury/$500+

with the contrapositive

~REUIRED REPORT for accident PI/$500+ --> incapable

For me the question of "report" or "not report" was the essence of the conditional chain, along with "capable" or "incapable". These are the terms we're actually considering in this argument, given that the accident meets certain requirements. So to me it made sense to lump those requirements under the "report" term. If we're dealing with an accident with personal injury of $500+, then this conditional rule speaks to the situation. If not, then we can't say anything. Understanding this allows for this simplified notation.

So the stem then tells us that Ted isn't required to report. Think of this as an additional premise to consider in conjunction with the conditional chain. So to sum up our evidence we have:

~incapable --> REQUIRED REPORT for accident personal injury/$500+

with the contrapositive

~REUIRED REPORT for accident PI/$500+ --> incapable

and

ted not required

The question asks for an inference. Using the conditional chain, and the new information about ted, we have to conclude something. In other words, Ted MUST be the SC. We can't END at ted. So we need to work off the contrapositive, where we already have ~required in the SC.

A) Knowing that we have to work off of the contrapositive, "if incapable" is the same as saying "if NC". The term "if NC" never triggers anything. This leads nowhere, eliminate.

B) "damage of $500" and "not required" together trigger the SC of the contrapositive. "incapable of reporting" then fits the SC of the contrapositive, and is what the answer choice says. We can infer this. Correct answer.

C) We know nothing about anyone who is not ted. And none of the conditional statements say anything about anyone else reporting. The conditional relationship doesn't speak to this, so this cannot be inferred. incorrect.

D) Like A, we're starting here with "if NC". This is a logical flaw, incorrect.

E) If this is true, we go nowhere in our conditional chain. Incorrect.

[cynthiaemesibe]

If answer choice E would have said "No one was injured in the accident AND the accident did not lead to property damage exceeding $500 but Ted was capable of reporting" would it have been the correct answer choice?

[andrewgong01]

==
(B) This looks good. This is the "if thing 1 doesn't apply, then thing 2 must apply".


Is the reason why B is further correct in this MBT question because it i phrased as a conditional an hence the validity of the answer choice is already "hedged" as a conditional in a hypothetical outcome it creates? We actually don't know what really happened to Ted and this answer choice is bascially giving us what would happen if the damage is above $500 but says nothing on what if it is the case that Ted is capable of reporting but it was a minor scratch? In other words, we say this is a MBT only under a specific hypothetical where the damage is in excess of $500 but we are not saying the damage was actually in excess of $500 ; just what if in the world that the damage was above $500 what do we know has to be true for sure? Well, since he's not reporting it we know that it must be the case, in this hypoethical world, he is not capable of reporting it.

[NatalieC941]

Patrick,

Your explanation largely makes sense, but I had a question about the original diagramming.

I originally diagrammed the: If A, then B unless C as such below:

A [driver inj OR driver exceed 500] AND [capable] --> required to report


When did you just indicated a slash "/" instead of diagramming the OR of the first phrase? How did you know to do this?

Because I diagrammed as such above, I then messed up big time when doing the contrapositive, and thus correctly finding the answer.

Any help to know what to do in the future would be appreciated!

Thanks,

[ohthatpatrick]

The slash I was using WAS to indicate "or".

If [a driver involved in an accident causing personal injury OR prop damage of $500+] and [capable of reporting acciendt], then [legally req'd to report].

The place I put the slash was a bit confusing, because it looked like I was saying "personal or property damage exceeding $500", but I was just trying to abbreviate.

Your rule looks mostly okay; I just don't know what the 2nd idea means:

A [driver inj OR driver exceed 500] AND [capable] --> required to report


If a driver is injured, or a driver exceeds 500?

[andreperez7]

TLDR Version:

Abstract Version:
Unless A, if B or C, then D = ~A AND [B or C] then D.

So if ~D, then the following relationship occurs: [if ~A, then ~B and ~C) = C or B then A.

Particulars- included version:

Unless incapable, then if injury or over $500 damage, then must report.

So if ~report, then [If ~incapable(i.e., capable), then ~ injury and ~over $500 damage] = [If Injury or over $500 damage then Capable.]

This relationship corresponds to answer B

Takeaway:
If A, then B, unless C = If ~C and A, then B.