Numismatist: In medieval Spain, most gold coins were minted from gold

Question

Numismatist: In medieval Spain, most gold coins were minted from gold mined in West Africa, in the area that is now Senegal. The gold mined in this region was the purest known. Its gold content of 92 percent allowed coins to be minted without refining the gold, and indeed coins minted from this source of gold can be recognized because they have that gold content. The mints could refine gold and produced other kinds of coins that had much purer gold content, but the Senegalese gold was never refined.

Which one of the following inferences about gold coins minted in medieval Spain is most strongly supported by the information the numismatist gives?

(A) Coins minted from Senegalese gold all contained the same weight, as well as the same proportion of gold

(B) The source of some refined gold from which coins were minted was unrefined gold with a gold content of less than 92 percent

(C) Two coins could have the same monetary value even though they differed from each other in the percentage of gold they contained

(D) No gold coins were minted that had a gold content of less than 92 percent

(E) The only unrefined gold from which coins could be minted was Senegalese gold

swirlsky · Answer

(A)Weight of coins is out of scope.'All' is an extreme word because CR talks about most gold coins and not all gold coins.

(B) Ans . If most coins were minted from Senegal , then some were from different source which has less purity of gold.

(D) 'No'is an extreme word.

(E) 'Only' is an extreme word.

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ballest127 · Answer

Hi  swirlsky ,

Based on your explanation, in choice B, so we need to assume that 
the less the purity of gold, the less percentage of gold content?

And if so, can we assume that to correctly infer?

Please explain.

Thank you.

mykrasovski · Answer

I don't get why B is better than E. The prompt says that Senegalese gold was never refined for coin production, and this is answer choice E.

VeritasPrepErika · Answer

If answer choice E said that Senegalese gold was never refined for coin production, it would be a valid inference ... but that isn't what answer choice E says. E doesn't say that  Senegalese  gold was  never  refined for coin production; it says that  non-Senegalese  gold was  always  refined for coin production. This can't be found anywhere in the passage. It's distinctly possible that other gold (although somewhat less pure than Senegalese gold) could still be used to mint coins — maybe a gold content of 90 or 91% would still be pure enough not to need refining. We just don't know, so E doesn't have to be true.

Correct answers for Inference questions (like this one) must be 100% true given the information in the passage, so it's extremely important to read the answer choices carefully. If we misread or make assumptions about what the answer choices say, we're likely to miss the question.

mykrasovski · Answer

Hi Erika, thanks much for addressing my question. After reading the prompt today and thinking very thoroughly, I totally understand why E is not a good option. The passage says that "most gold coins were minted from Senegalese gold which had high quality", and one can conclude that there could possibly be other sources of gold and there are no data about the quality of the gold from those hypothetical regions. So, it is possible that there was a region (or even a few) which had high quality gold that did not have to be refined, i.e. it was comparable to gold from Senegal. So, E could be true but does not necessarily have to be true. Is my reasoning correct?

I also realized that E is overly strong because of "the only" language. Generally, strong statements tend to be good answer choices for Weaken / Strengthen questions, but not for Assumption & Inference questions. So, one at least should be suspicious about option E in this particular question. Would you generally agree with my observations?

VeritasPrepErika · Answer

Solid reasoning! I also like that you're looking out for extreme language — and "only" is a really classic example. Should we rule an answer out immediately because of extreme language? No. Sometimes extreme things are true. But we shouldn't give it any more attention until we've ruled out less extreme, more plausible answer choices. This will save us from wasting time and mental energy on wrong answer choices and accidentally convincing ourselves of something that isn't likely to be true.

nurba92 · Answer

Hello everyone,

I rejected B because most can mean all as well (I learned this in e-gmat, though I still don't understand why), and the last sentence says the mints COULD refine and produce OTHER KINDS OF COINS (it doesn't say they did refine)

Can anyone make all the staff above clear for me?

Doer01 · Answer

Hi  nurba92  ,
 Most is >50% but <100%.
Having said that, most, but not all, coins in medieval Spain were made from gold mined from Senegal. That means, there was still some % of coins made from gold that was not from Senegal, irrespective of what gold content they had. 
Now, lets look at the choices.
A is easy to reject as weight of a coin is not mentioned in the argument.
B does align with our argument. Keep it as a contender for now.
C talks about value of two different coins. Again, it’s not mentioned anywhere in the given argument. Incorrect.
D Whether or not gold coins were minted if the gold content was less than 92% is not given in the argument. We could only say certain thing about MOST of the coins, such as good content in those that were minted from Senegalese gold. Nothing more than that. incorrect.
E Now, making such a statement that Senegalese gold was the ONLY gold that did not need any refining is a strong statement and we cannot make such a statement unless it is given that no other gold had such purity level as Senegalese that it did not need to be refined. 
So, B is the only statement that has a proof of being 100% correct. 
Hence, B is the winner.
Hope this helps.

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nurba92 · Answer

Doer01 ,
In the stimulus, there is no mention of "not all". And as I said, I still don't understand why most can mean all, but e-gmat says so (since they are way more experienced, I memorized this staff)
Can you tell me is there any way how we can infer "all" from "most" or it is totally incorrect?
Thanks

Doer01 · Answer

Hi  nurba92 ,
 "but not all" is something that could be inferred when "most" is used. That's why I had put inside a comma pair. 
Second, Most cannot mean all as both are different quantity markers according to CR Bible. I took e-gmat course too and I do not remember most being translated to all.

nurba92 · Answer

Guys,
If most means 51-99%, its logical opposite is 50% or less, but what about 100% in this very case? (I don't mean 100% is all staff, I mean that when considering "most", 100% is absent both in itself and in its logical opposite)
Thanks

garcmillan · Answer

This is an inference question, so let's try to find so inferences that are not explicitly stated in the argument before jumping into the options. This is just to help us think about the argument

1ºPremise: Coins were minted in Senegal
2ºPremise: Gold from Senegal purest known --> 92% (no need of refinining coins) --> cold recognizable
3ºPremise: Possible to produce coins >92% gold. Senegalese coin never refined
Possible gaps:

- Coins in Spain can't have >92% of gold without refinement
- Not all coins in Spain are made out of African gold (it says most)
- Coins in Spain with 92% of gold are recognizable

Let's check answer now:

(A) Coins minted from Senegalese gold all contained the same weight, as well as the same proportion of gold

Same weight? Coin weight is never discussed.  Incorrect

(B) The source of some refined gold from which coins were minted was unrefined gold with a gold content of less than 92 percent

This is indeed possible because it says that "most" of the coins were made ut of African gold. So that means, some others are not and this means that the unrefined gold is coming from sources with <92%.  Correct

(C) Two coins could have the same monetary value even though they differed from each other in the percentage of gold they contained

This is possible but we can't definitely infer this from the argument.  Incorrect

(D) No gold coins were minted that had a gold content of less than 92 percent

Not true. It can have 92% and even more if refined and less than 92% too Incorrect

(E) The only unrefined gold from which coins could be minted was Senegalese gold

Again not true. There may be other coins with unrefined gold coming from another source. But these coins will have less than 92% of gold for sure.  Incorrect 
 
OPTION B

Jaishankersharma · Answer

Explanation why B is correct:- If you read carefully segnegal gold is "PUREST" and its gold content is 92%.It means other mines will be producing less than 92% purity Gold.So, B is correct.

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Numismatist: In medieval Spain, most gold coins were minted from gold

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Numismatist: In medieval Spain, most gold coins were minted from gold

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