Critical Reasoning

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.

Please explain all the answer choices .

I choose [spoiler]E)[/spoiler]

Explanation:

[spoiler]
P1. The explorer had samples examined for gold and they found high content.
P2. They then made expeditions but found nothing.
P3. Modern samples indicated low content.
C1. The method used to analyze the samples must have been inaccurate.

A) INCORRECT, why didn't the expeditions find the gold, then?
B) INCORRECT, why are the modern tests results negative, then?
C) INCORRECT, irrelevant.
D) INCORRECT, irrelevant.
E) CORRECT, if gold had indeed been added, it'd explain both why they the 16th century test differs from the modern test, and why the expeditions didn't find anything. Since gold wasn't added, the only other logical conclusion is that the method was inaccurate.


[/spoiler]

My answer is E.

It is the only logical assumption that could be made!

I thought this was fairly easy. E stood out to me because it really makes sense and none of the others does. I think if you understand the statement and question then you should be able to understand why E is the only good choice. Not to mention, E is actually a very logical and correct answer (much better than the others.)

GMATMadeEasy wrote: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.

Please explain all the answer choices .

E is the correct answer and this is a CR from OG 11