Frobisher, a sixteenth-century English explorer, had soil

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Frobisher, a sixteenth-century English explorer, had soil samples from Canada's Kodlunarn Island examined for gold content. Because high gold content was reported, Elizabeth I funded two mining expeditions. Neither expedition found any gold there. Modern analysis of the island's soil indicates a very low gold content. Thus the methods used to determine the gold content of Frobisher's samples must have been inaccurate. Which of the following is an assumption on which the argument depends?

A. The gold content of the soil on Kodlunarn Island is much lower today than it was in the sixteenth century.
B. The two mining expeditions funded by Elizabeth I did not mine the same part of Kodlunarn Island.
C. The methods used to assess gold content of the soil samples provided by Frobisher were different from those generally used in the sixteenth century.
D. Frobisher did not have soil samples from any other Canadian island examined for gold content.
E. Gold was not added to the soil samples collected by Frobisher before the samples were examined.

[spoiler]OA: Will be posted later. Please discuss each answer choice in detail[/spoiler]

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by mundasingh123 » Sun May 15, 2011 5:18 am
is this gmat prep
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by Anahatha » Sun May 15, 2011 5:34 am
Answer : E

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by aspirant2011 » Sun May 15, 2011 7:15 am
Anahatha wrote:Answer : E
Hi Anahatha,

Can you please explain in detail how you reached to E option..........

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by aspirant2011 » Sun May 15, 2011 7:16 am
mundasingh123 wrote:is this gmat prep
Hi Mundasingh,

Nopes I found it in Sandeep Gupta's Ivy GMAT......

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by Anahatha » Sun May 15, 2011 8:06 am
The coclusion : ' methods used to determine the gold content of Frobisher's samples must have been inaccurate'

The evidence is that the methods wrongly reported a high content of gold. An assumption for this coclusion to be true is that Frobisher did not add the gold before testing. If he did so, then the methods used are accurate.

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by aspirant2011 » Sun May 15, 2011 8:20 am
Anahatha wrote:The coclusion : ' methods used to determine the gold content of Frobisher's samples must have been inaccurate'

The evidence is that the methods wrongly reported a high content of gold. An assumption for this coclusion to be true is that Frobisher did not add the gold before testing. If he did so, then the methods used are accurate.
I am not able to understand why does Forbisher needs to add Gold??????

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by mundasingh123 » Sun May 15, 2011 9:00 am
aspirant2011 wrote:
mundasingh123 wrote:is this gmat prep
Hi Mundasingh,

Nopes I found it in Sandeep Gupta's Ivy GMAT......
hat a coincidece ! The same problem has been tagged as Gmat Prep on a fe BTG / Gmat Club Threads .
I Seek Explanations Not Answers

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by aspirant2011 » Sun May 15, 2011 9:01 am
mundasingh123 wrote:
aspirant2011 wrote:
mundasingh123 wrote:is this gmat prep
Hi Mundasingh,

Nopes I found it in Sandeep Gupta's Ivy GMAT......
hat a coincidece ! The same problem has been tagged as Gmat Prep on a fe BTG / Gmat Club Threads .
yup I also searched google and found it was written that its of GMAT Prep...............CR's make me crazy and I am really weak in English.....................:-(

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by mundasingh123 » Sun May 15, 2011 9:08 am
aspirant2011 wrote:
mundasingh123 wrote:
aspirant2011 wrote:
mundasingh123 wrote:is this gmat prep
Hi Mundasingh,

Nopes I found it in Sandeep Gupta's Ivy GMAT......
hat a coincidece ! The same problem has been tagged as Gmat Prep on a fe BTG / Gmat Club Threads .
yup I also searched google and found it was written that its of GMAT Prep...............CR's make me crazy and I am really weak in English.....................:-(
Ok in case you were serious about you r last post and did not get the logic behind why did Frobisher add gold , you dont need to bother about whether it makes sense or the the motive behind it ya , u can get better at English
Have you taken leave or something cos i see u active the wholde day
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by aspirant2011 » Sun May 15, 2011 9:11 am
nopes haven't taken any leave........it's only sat and sundays when I am active mostly :-(..........

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by Anahatha » Sun May 15, 2011 10:47 am
I chose E because it eliminates a possible alternative explanation for the high content of gold (defender assumption) . Negate this answer. If he DID add gold then the method he used is accurate since the soil will have high content of cold. This will weaken the conclusion ('method inaccurate').

In btw, is this the right answer???

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by Brian@VeritasPrep » Mon May 16, 2011 8:19 am
Thanks for the invitation to chime in here - and great use of the Assumption Negation Technique, Anahatha! That's exactly how I'd look at this one:

We're concluding that THE METHODS to determine the gold content were inaccurate. And we're doing that because that study suggested that there was plenty of gold, but gold wasn't found in the two mining expeditions. Essentially the argument goes:

Study found high gold content, but mining expeditions found no gold. Therefore, study methods were wrong.

The best part of that Assumption Negation Technique, to me, is that it turns these questions into a type of "weaken" question - you're looking to attack the argument. Immediately I think that this argument is weak. Why? Because it may not have been the methods that were wrong...it could have been some other flaw in the study situation. Perhaps there was one small pocket of gold that he tested (correctly) and by the time they mobilized the expedition someone had already gotten to it. Or perhaps someone tampered with the sample (as E will elude to) to convince Elizabeth to fund the operation.

If you negate choice E, it directly weakens that conclusion as we just proposed above:

Gold WAS (not 'was not') added to the samples before the samples were examined.

This hits that tampering possibility - if the samples were contaminated, even the most accurate study methods would provide a false result. And so E is an assumption that the original argument made - that it wasn't a tampered sample, but rather a faulty test.


For assumption questions, it's important to read the argument critically; the correct answer seldom provides compelling NEW evidence...it usually just clarifies the existing evidence in a way to make it more effective. So if you're already poking at the argument for flaws/weaknesses, you'll better see the need for that supporting evidence in the correct answer. And if you use Assumption Negation, you can turn it directly into a weaken question, and we tend to be really good at those. Who among us doesn't like to criticize?
Brian Galvin
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by mundasingh123 » Mon May 16, 2011 9:08 am
but the addition of gold is new evidence here , isnt it ?
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by aspirant2011 » Mon May 16, 2011 9:56 am
Brian@VeritasPrep wrote:Thanks for the invitation to chime in here - and great use of the Assumption Negation Technique, Anahatha! That's exactly how I'd look at this one:

We're concluding that THE METHODS to determine the gold content were inaccurate. And we're doing that because that study suggested that there was plenty of gold, but gold wasn't found in the two mining expeditions. Essentially the argument goes:

Study found high gold content, but mining expeditions found no gold. Therefore, study methods were wrong.

The best part of that Assumption Negation Technique, to me, is that it turns these questions into a type of "weaken" question - you're looking to attack the argument. Immediately I think that this argument is weak. Why? Because it may not have been the methods that were wrong...it could have been some other flaw in the study situation. Perhaps there was one small pocket of gold that he tested (correctly) and by the time they mobilized the expedition someone had already gotten to it. Or perhaps someone tampered with the sample (as E will elude to) to convince Elizabeth to fund the operation.

If you negate choice E, it directly weakens that conclusion as we just proposed above:

Gold WAS (not 'was not') added to the samples before the samples were examined.

This hits that tampering possibility - if the samples were contaminated, even the most accurate study methods would provide a false result. And so E is an assumption that the original argument made - that it wasn't a tampered sample, but rather a faulty test.


For assumption questions, it's important to read the argument critically; the correct answer seldom provides compelling NEW evidence...it usually just clarifies the existing evidence in a way to make it more effective. So if you're already poking at the argument for flaws/weaknesses, you'll better see the need for that supporting evidence in the correct answer. And if you use Assumption Negation, you can turn it directly into a weaken question, and we tend to be really good at those. Who among us doesn't like to criticize?
thanks a lot Brian :-)..........when I first looked at the question I just thought that if we are not adding something from outside then we are not contaminating and therefore, the methods need not to be inaccurate :-(............from now onwards for assumption questions I would apply negation technique and will see which option most destroys the conclusion...........would be really thankful to you if you can guide me on how to proceed for Strengthen and Weaken CR's :-)