Excavations of the Roman city of Sepphoris have uncovered numerous det

Hi limitlessliu,

It's great that you're thinking carefully about questions like this However, here you may be slightly overthinking it a bit. Remember that we can (and should) make reasonable assumptions in order to answer these kinds of questions. Also remember that we are always looking for the best answer, which may not be a perfect one. So even though this answer many not be perfect, it's exactly the kind of answer that you'll see on the actual GMAT, so it's good to learn to recognize the kind of thought process that should be followed here.

I hope that makes sense!
-Carolyn

Excavations of the Roman city of Sepphoris have uncovered numerous detailed mosaics depicting several readily identifiable animal species : a hare, a partridge, and various Mediterranean fish. Oddly, most of the species represented did not live in the Sepphoris region when these mosaics were created. Since identical motifs appear in mosaics found in other Roman cities, however, the mosaics of Sepphoris were very likely created by traveling artisans from some other part of the Roman Empire.

Hi,

Would like to give my two cents if helpful :-


(A) The Sepphoris mosaics are not composed exclusively of types of stones found naturally in the Sepphoris area. -->Stones are not in issue here. The motifs and artists are.

(B) There is no single region to which all the species depicted in the Sepphoris mosaics are native. --> Negate this.
There is a single region to which all the species depicted in the Sepphoris mosaics are native. Still artist will have to travel if that plave is not in city. Hence, travelling artist.

(C) No motifs appear in the Sepphoris mosaics that do not also appear in the mosaics of some other Roman city. --> Negate this. Motifs appear in the Sepphoris mosaics that do not also appear in the mosaics of some other Roman city. Still cannot conclude that the artists did not travel.

(D) All of the animal figures in the Sepphoris mosaics are readily identifiable as representations of known species.--> Even if it is not identifiable, the artists could be travelling.

(E) There was not a common repertory of mosaic designs with which artisans who lived in various parts of the Roman Empire were familiar. --> Negate this. Negation will mean artists won't have necessity to travel.

Thanks!

Hey,

I stuck between B and E. My reasoning to favor B is that if there is no single region to which all the species are native, then the people who created those mosaics are coming from various regions. Therefore, they are considered travelling artisans.

Please explain the flaw in my reasoning.

Thanks in advance.

A. The Sepphoris mosaics are not composed exclusively of types of stones found naturally in the Sepphoris area.
Out of scope – doesn’t matter what TYPE of stone/material the mosaics were COMPOSED of…

B. There is no single region to which all the species depicted in the Sepphoris mosaics are native.
This doesn’t bridge the gap to the fact that it could’ve all been made by traveling artisans.

C. No motifs appear in the Sepphoris mosaics that do not also appear in the mosaics of some other Roman city.
This doesn’t have to be true. If so, cool. If not, who cares?

D. All of the animal figures in the Sepphoris mosaics are readily identifiable as representations of known species.
This goes directly against the conclusion. Weakener. If all the animal figures were known, then why would specifically traveling artisans been the probable people who made these mosaics.

E. There was not a common repertory of mosaic designs with which artisans who lived in various parts of the Roman Empire were familiar.
So this bridges it. If there WAS a common repertory then it would be silly to think it was traveling artisans who would have “very likely” created the mosaics…

I believe that I find myself in this trap sometimes as well.

A statement can strengthen or support the conclusion, yet NOT be a necessary assumption to get from the Supporting Premises to the Conclusion.

I think if B were true, you could say that it makes it slightly more likely that traveling artisans created these mosaics. After all, if they are from regions all over, it might make sense that a traveling artisan would have drawn these.

However, is the statement from B absolutely necessary for the logic of the argument to work?

The author says these mosaics contained pictures of animals that are not local. Based on this major premise, he concludes it must have been a traveling artisan that made these mosaics.

B isn’t necessary to “connect” or “glue” the facts to the Conclusion. Even if there is not a single region to which all the animals are native, is it necessary to assume this fact to conclude that traveling artisans made the mosaics? Not really.

However, negate E. The whole argument is based pretty much on this fact that the animals don’t exist in the city, so some traveling artisan must have made them.

But if there WERE a common knowledge base, the artisans in the city could have easily made these mosaics and the author’s argument doesn’t make as much sense anymore.

Does anything help? I hope it came across clear, I don’t envy any GMAT tutor who has to explain these questions on a daily basis.




Posted from my mobile device

I think it would be helpful to get an expert view on the use of negatives here, as upon first read the options sound a bit gibberish.
For example, in my mind how I was translating:
a. Sepphoris mosaics contain some or no stones found naturally in the area
b. Species are a from more than one region
Etc.

You have to consider the logic of what a choice says to determine how to negate it.

A. The Sepphoris mosaics are not composed exclusively of types of stones found naturally in the Sepphoris area.

B. There is a no single region to which all the species depicted in the Sepphoris mosaics are native.

C. No Some motifs appear in the Sepphoris mosaics that do not also appear in the mosaics of some other Roman city.

D. All None of the animal figures in the Sepphoris mosaics are readily identifiable as representations of known species.

E. There was not a common repertory of mosaic designs with which artisans who lived in various parts of the Roman Empire were familiar.

- We're told that excavations of the city of Sepphoris uncovered mosaics depicting several animal species.
- Most of these species did not live in this region at the time.
- The argument concludes that since identical motifs appear in mosaics found in other Roman cities, the mosaics of Sepphoris were very likely created by traveling artisans from some other part of the Roman Empire.

In short: Since the species didn't live in the region, the mosaics were created by traveling artisans from another region.

Before looking at the choices, we can see that this argument is fairly weak. Can we not gather information about these species from elsewhere?

Let's look through the options:

A - Types of stones is irrelevant. Remember, the conclusion is that the mosaics of Sepphoris were very likely created by traveling artisans from some other part of the Roman Empire. Whether the types of stones were native to the region is not important.

B - Do the species all have to be from a single region? No. They species can be from two, three, or even four regions. This distinction is not necessary.

C - The argument doesn't depend on this. The motifs can also appear in the mosaics of some other Roman city.

D - Do all the animal figures have to be readily identifiable? Perhaps there are some that are not identifiable. This statement is not a necessary assumption to the argument.

E - Interesting. If there was a common repertory of mosaic designs among artisans, then it's possible the mosaics were created by artisans in the Sepphoris. E is the answer.

Excavations of the Roman city of Sepphoris have uncovered numerous detailed mosaics depicting several readily identifiable animal species : a hare, a partridge, and various Mediterranean fish. Oddly, most of the species represented did not live in the Sepphoris region when these mosaics were created. Since identical motifs appear in mosaics found in other Roman cities, however, the mosaics of Sepphoris were very likely created by traveling artisans from some other part of the Roman Empire.

Which of the following is an assumption on which the argument depends?


(A) The Sepphoris mosaics are not composed exclusively of types of stones found naturally in the Sepphoris area.

(B) There is no single region to which all the species depicted in the Sepphoris mosaics are native.

(C) No motifs appear in the Sepphoris mosaics that do not also appear in the mosaics of some other Roman city.

(D) All of the animal figures in the Sepphoris mosaics are readily identifiable as representations of known species.

(E) There was not a common repertory of mosaic designs with which artisans who lived in various parts of the Roman Empire were familiar.


Let’s look at the stimulus given.


Premises- Excavations of the Roman city of Sepphoris have uncovered numerous detailed mosaics depicting several readily identifiable animal species : a hare, a partridge, and various Mediterranean fish.
Oddly, most of the species represented did not live in the Sepphoris region when these mosaics were created
Since identical motifs appear in mosaics found in other Roman cities (reason)

Conclusion- the mosaics of Sepphoris were very likely created by traveling artisans from some other part of the Roman Empire.


We need to find the assumption of the argument.
Let’s take a look at the options.


(A) The Sepphoris mosaics are not composed exclusively of types of stones found naturally in the Sepphoris area.

The conclusion is that the mosaics of Sepphoris were very likely created by traveling artisans from some other part of the Roman Empire because these mosaics depict animals not found in the Sepphoris region but found in other parts of the Roman Empire.
Whether the mosaics were composed of stones found in the Sepphoris region or some other region is not relevant to the argument. Eliminate.

(B) There is no single region to which all the species depicted in the Sepphoris mosaics are native.
Where the species belong is again out of scope. The conclusion is that these motifs were created by traveling artisans. We need to find an option that helps us confirm that. Eliminate.

(C) No motifs appear in the Sepphoris mosaics that do not also appear in the mosaics of some other Roman city.
Same as B. Eliminate

(D) All of the animal figures in the Sepphoris mosaics are readily identifiable as representations of known species.
So? Does it prove that the motifs were created by traveling artisans? Eliminate

(E) There was not a common repertory of mosaic designs with which artisans who lived in various parts of the Roman Empire were familiar.

Bingo. Option E says that there was no common repertory of mosaic designs with which artisans who lived in various parts of the Roman Empire were familiar. This confirms that they would have seen/ come to know of these animals found in the designs when they travelled to other parts of the Roman Empire.
Correct.

VP
GMAT SME

GMATNinja, MartyTargetTestPrep, CrackverbalGMAT

Hello,

for assumptions questions, if we don't assume the answer choice to be true, the conclusion made in the argument can't be true.

Negate (E): There was a common repertory of mosaic designs with which artisans who lived in various parts of the Roman Empire were familiar.

How can we conclude from negating (E) that it was NOT likely that traveling artisans who made the mosaics? It seems to only weaken the conclusion, but not completely eliminate it.

The negated version of (E) doesn't prove the conclusion incorrect, but it does destroy the support for the conclusion that it is likely that traveling artisans made the mosaics. So, (E) is an assumption upon which that support depends.

Thanks a lot.

I still have my doubts:

A necessary assumption must be true for the conclusion to follow.

Let's assume not (E) and also assume that it was custom that in each city, only artisans from other regions were allowed to make to mosaics, and also that most people who were artisans were traveling artisans. We could STILL reach the conclusions that it were likely traveling artisans who made the mosaics.

Not (E) doesn't destroy the argument and hence is not necessary. Here is what I mean in an example, take the following statement:

There are many yellow cars in the city.
A necessary assumption is that there are cars in the city. If we don't assume that, there can never be any kind of cars, not to mention yellow ones, in the city.

Thoughts?

Which of the following is an assumption on which the argument depends?
Conclusion ----> Mosaics were created by travelling artisans from “other parts of roman empire”
Why?----> because the animals species depicted in mosaics did not live in Sepphoris when the mosaics were created. However, we found the similar depiction in other roman cities.


(A) The Sepphoris mosaics are not composed exclusively of types of stones found naturally in the Sepphoris area. --------------- stones? Not our concern. INCORRECT

(B) There is no single region to which all the species depicted in the Sepphoris mosaics are native. -------- we are not concerned with what these species are native of. INCORRECT

(C) No motifs appear in the Sepphoris mosaics that do not also appear in the mosaics of some other Roman city. -------- it says that all motifs in S appear in some other roman city. It does not strengthen the argument. INCORRECT

(D) All of the animal figures in the Sepphoris mosaics are readily identifiable as representations of known species. ------------- if this is true, then okay we can identify the species, but this does not strengthen the argument. INCORRECT

(E) There was not a common repertory of mosaic designs with which artisans who lived in various parts of the Roman Empire were familiar ------------ if this is true then the mosaic must have been made by travelling artisans. There was no other way to access the knowledge. CORRECT

Hi - If I negate (C) - i think, this is the inference :

There are some motifs (lets say 10% of all all Sepphoris mosaics ) that are unique to Sepphoris mosaics only.

These 10 % motifs DO NOT APPEAR in the mosaics of other roman cities (i.e. these 10 % specifically ARE UNIQUE to Sepphoris mosaics.)

So, doesnt this 10 % unique MOTIFS in the Sepphoris mosaics IMPLY that

TRAVELLING ARTISANS did not paint these 10 % or could travelling artisans have painted these 10 % unique motifs only

Hence - i thought (C) did weaken the conclusion a bit because these 10 % of motifs (That are unique to Sepphoris mosaics) are not made by TRAVELLING ARTISANS.

ReedArnoldMPREP GMATNinja MartyTargetTestPrep avigutman

My question is on interpreting the argument, specifically the yellow highlight below.



When you read the yellow highlight – what goes through your mind ? Does the yellow imply :

• Every motif found in Sepphoris mosaics HAS AN IDENTICAL motif somewhere else [JD – I personally thought thats what the yellow meant ]
  
  OR
  
  
• SOME Sepphoris' MOTIFS are identical ONLY. Not EVERY MOTIF but **SOME MOTIFS** ARE IDENTICAL (one could assume, a hare motif or a partridge motif or a Mediterranean fish motif). There are some Sepphoris MOTIFS unique to Sepphoris
  
  OR
  
  
• BOTH are probable. We can't say just yet without more information as of yet.
  
  

Which did you believe or did you not know, which to believe ?

Thank you

The key is to see what matters. So, what goes through my mind is that motifs identical to the motifs already mentioned in the passage appear in mosaics in other cities. The passage does not say whether all motifs or some motifs in the mosaics in Sepphoris are matched identically in mosaics in other cities. So, at that point in going through the question, I don't care because there's no reason to care.

Now, if I needed to decide whether the information provided implies that there are motifs in other cities identical to all motifs in mosaics in Sepphoris, I would say that that idea is not supported. There could be motifs in the mosaics in Sepphoris that are not discussed in the passage.

However, I think that, with regard to the mentioned motifs in mosaics in Sepphoris that involve "a hare, a partridge, and various Mediterranean fish," all of those motifs are matched by identical ones in other cities.