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Uranium Resources - GMAT prep

by sunnyjohn » Tue Nov 17, 2009 10:34 pm

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Most of the world's supply of uranium currently comes from the mines. It is possible to extract uranium from seawater, but the cost of doing so is greater than the price that Uranium fetches on the world market. Therefore, until the cost of extracting uranium from seawater can somehow be reduced, this method of obtaining uranium is unlikely to be commercially viable.

Which of the following would it be most useful to determine in evaluating the argument?

a. Whether the uranium in deposits on land is rapidly being depleted
b. Whether most uranium is used near where it is mined
c. Whether there are any technological advances that show promise of reducing the costs of extracting uranium from seawater
d. Whether the total amount of Uranium in seawater is significantly greater than the total amount of uranium on land
e. Whether uranium can be extracted from freshwater at a cost similar to the cost of extracting it from seawater.

I am stuck between A and C?
Any test guru can help how to approach "Evaluating the argument" Questions type?
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by papgust » Tue Nov 17, 2009 10:55 pm

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sunnyjohn wrote:Most of the world's supply of uranium currently comes from the mines. It is possible to extract uranium from seawater, but the cost of doing so is greater than the price that Uranium fetches on the world market. Therefore, until the cost of extracting uranium from seawater can somehow be reduced, this method of obtaining uranium is unlikely to be commercially viable.

Which of the following would it be most useful to determine in evaluating the argument?

a. Whether the uranium in deposits on land is rapidly being depleted
b. Whether most uranium is used near where it is mined
c. Whether there are any technological advances that show promise of reducing the costs of extracting uranium from seawater
d. Whether the total amount of Uranium in seawater is significantly greater than the total amount of uranium on land
e. Whether uranium can be extracted from freshwater at a cost similar to the cost of extracting it from seawater.

I am stuck between A and C?
Any test guru can help how to approach "Evaluating the argument" Questions type?
I feel that the answer should be A
Because, the author states that if the cost of extracting uranium from seawater can somehow be reduced, then this method could be efficient. The author needs to confirm if the uranium in mines is rapidly depleted before concluding the argument. So, this answer makes sense.

C unnecessarily talks about technological advances with which the author does not depend on to make the argument valid.
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by sunnyjohn » Tue Nov 17, 2009 11:09 pm

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papgust wrote: Because, the author states that if the cost of extracting uranium from seawater can somehow be reduced, then this method could be efficient. The author needs to confirm if the uranium in mines is rapidly depleted before concluding the argument. So, this answer makes sense.

C unnecessarily talks about technological advances with which the author does not depend on to make the argument valid.
hmm, I have different point of view...Because Author said
two source of uranium - land and sea
extracting from land - cheaper
extracting from sea - expensive - so we don't use it.

so in order to use sea's uranium, the extraction cost should be less.

What is the problem with two resources of uranium? Why does author needs to confirm that uranium at land has to be finished before we start using the Sea's uranium.
In A - suppose the uranium at land is depleting fast, then in that - no matter how much is the cost of extraction, we have no other alternative. so Author doesn't stand anywhere in that case..!
Are we weakening author's argument here?

i m confuse..!
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by papgust » Wed Nov 18, 2009 12:04 am

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sunnyjohn wrote:
papgust wrote: Because, the author states that if the cost of extracting uranium from seawater can somehow be reduced, then this method could be efficient. The author needs to confirm if the uranium in mines is rapidly depleted before concluding the argument. So, this answer makes sense.

C unnecessarily talks about technological advances with which the author does not depend on to make the argument valid.
hmm, I have different point of view...Because Author said
two source of uranium - land and sea
extracting from land - cheaper
extracting from sea - expensive - so we don't use it.

so in order to use sea's uranium, the extraction cost should be less.

What is the problem with two resources of uranium? Why does author needs to confirm that uranium at land has to be finished before we start using the Sea's uranium.
In A - suppose the uranium at land is depleting fast, then in that - no matter how much is the cost of extraction, we have no other alternative. so Author doesn't stand anywhere in that case..!
Are we weakening author's argument here?

i m confuse..!
In my opinion, we are not weakening the argument. We are trying to consider a statement that would help us before evaluating the argument. I tried to think in many ways and i still feel that A is apt.

It's time for others to step into the discussion and throw some light!
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by viju9162 » Wed Nov 18, 2009 1:52 am

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I am stuck between C and D. However, I go with C.

The author concludes that extraction of uranium from sea water is viable only if the cost is not too high for sea water mining. Hence, what do we need to ask to evaluate the above argument.


C states that do we have sufficient technology that will aid in uranium extraction from sea water at low cost.
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by gmatmachoman » Wed Nov 18, 2009 4:13 am

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IMO C:

I feel the argument discuss about commercial viability of available resources in sea water. The author is NOT really bothered
about finding a ALTERNATE SOURCE when the existing coal mine depletes but in BOTHERED about how beneficially we can use it if any technological advances could help his purpose. The alternate source is already identified as SEAWATER.Its just that a NEW means has to be identified for commercial utilization.

"It is possible to extract uranium from seawater"...makes clear that alternat source is already there, author is concerened about its commercial viability. So IMO C does the job.
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by okigbo » Wed Nov 18, 2009 2:14 pm

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As to the choice btween C and A, they are both relevant, but which is "most" relevant? Well, this comes to the word "rapidly" in A. If the supply of uranium from land is being rapidly depleted, this will greatly change the supply available, and thus the price on the market. Very important. C, meanwhile, only tells us that there will be a reduction in the cost of extracting uranium from the sea. We do not know whether that reduction would even be enough to make up for the current cost disparity, much less make such a venture profitable -mgmat
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by heshamelaziry » Wed Nov 18, 2009 8:21 pm

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IMO A, but I can't get clear vision. if yes for A, then what ? an if No for A, then ?
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by sunnyjohn » Wed Nov 18, 2009 9:41 pm

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OA: A

I am not still not convinced why A is the answer. Any expert please comment...!
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by lav » Wed Nov 18, 2009 10:27 pm

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@sunny john .. wats the source of ques ?? In my opinion ans shoudl be C

as ques stem uses MOST . so here is why i choose C over between A.

Option A :: Suppose uranium deposits on land have has rapidly depleted ... does it effect the cost of extracting uranium fron land .... it depends on method of extraction actually which is not mentioned here we don't know for sure if method of extraction is dependent on ??
if NO .. then even If deposit is 90% or it is 10% cost is same in both cases.
if YES .. then cost generally increase with decrease in concentration .. hence in this condition A is right

Option C "Whether there are any technological advances that show promise of reducing the costs of extracting uranium from seawater" If ans is YEs then its cheaper to get uranium from sea if NO then its its cheaper to get uranium from land.

In my opinion OPtion C is better ... Option A has ifs/buts
Whats the source of ques ??
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by papgust » Wed Nov 18, 2009 10:47 pm

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Hi lav,

I think its not a good idea of bringing in percentages in reasoning when the stimuli never talks about percentages. Just think of this CR as a Demand-Supply concept. You will see that A makes sense.
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by Testluv » Wed Nov 18, 2009 10:50 pm

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sunnyjohn wrote:Most of the world's supply of uranium currently comes from the mines. It is possible to extract uranium from seawater, but the cost of doing so is greater than the price that Uranium fetches on the world market. Therefore, until the cost of extracting uranium from seawater can somehow be reduced, this method of obtaining uranium is unlikely to be commercially viable.

Which of the following would it be most useful to determine in evaluating the argument?

a. Whether the uranium in deposits on land is rapidly being depleted
b. Whether most uranium is used near where it is mined
c. Whether there are any technological advances that show promise of reducing the costs of extracting uranium from seawater
d. Whether the total amount of Uranium in seawater is significantly greater than the total amount of uranium on land
e. Whether uranium can be extracted from freshwater at a cost similar to the cost of extracting it from seawater.

I am stuck between A and C?
Any test guru can help how to approach "Evaluating the argument" Questions type?
Hi Sunnyjohn,

In order to be "useful" in evaluating the argument an answer choice has to fall directly within the scope of the argument. Accordingly, in evaluate the argument or relevant information questions it is important to determine the author's central assumption. The correct answer will always be closely related to the author's assumption.

It is also useful to view these questions as being hybrid strengthen/weaken. The answer choices will often be questions. Here, all of the answer choices begin with "whether." Ask of each answer choice whether it is the case or whether it is not. The correct answer will be something where if it goes one way, it will strengthen the argument, and if it goes another way, it will weaken the argument.

Here, the author has two main pieces of evidence: 1) most of the world's supply of uranium currently comes from mines and 2) it is costly to extract uranium from the sea. He uses these two pieces of evidence to conclude that this method will remain commercially unviable (unless the cost can be reduced).

Let's look at choices A and C:

a. Whether the uranium in deposits on land is rapidly being depleted

Well, what if uranium from land was not being depleted? Then the argument is strengthened, as the supply of coal won't be diminished, and so there will be no (economic) reason to turn to the sea.

And what if uranium from land WAS being rapidly depleted? Then the supply of coal would dry up, coal prices would most likely go up, and all of a sudden it might be commercially viable (profitable) to mine coal from the sea--the argument is weakened.

In fact, this answer choice is essentially the author's assumption. It is a necessary assumption of the argument that the coal from mines continue to provide a ready supply. Denial test: if coal from mines dried up, it may well be economically (commercially) viable to turn to the sea, and the argument falls apart. Figuring out the assumption before going to the answer choices is of huge benefit in these questions. Remember you can always verify
whether you've figured out the necessary assumption correctly by applying the denial test.

c. Whether there are any technological advances that show promise of reducing the costs of extracting uranium from seawater

Well, what if there were? The author would simply remind you that he said "..until the cost of extracting uranium from seawater can somehow be reduced..." The author acknowledged that mining coal from the sea might be worth it if they could figure out a cheaper way of doing it. Therefore, determining whether there are any technological advances that could make it cheaper would not be very useful in evaluating the merits of his argument.
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by DeepakYakkundi » Wed Nov 18, 2009 10:59 pm

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The conclusion of arguement is "this method(the current method of extracting uranium from sea) of obtaining uranium is unlikely to be commercially viable."
The reason is the cost of extracting uranium from seawater using the current method is higher than that of extracting from mines.

NOw we have to find an answer choice whose answer yes/no should strengthen/weaken the conclusion.

Ans choice (c) is Whether there are any technological advances that show promise of reducing the costs of extracting uranium from seawater and is the correct answer.

An 'yes' to this question results in weakening the conclusion. Technological advances -> new methods -> reduced costs -> obtaining uranium from seawater will be commercially viable.

An 'No' to this question results in strengthening the conclusion. No Technological advances -> No new methods -> higher costs -> obtaining uranium from seawater will not be commercially viable.
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by Testluv » Wed Nov 18, 2009 11:11 pm

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Commercial viability has to do with whether or not it is worth it. In other words "commerical viability" is the same as "economic feasbility". If the supply of coal from mines depletes, the demand will remain unaffected, and the prices of coal will shoot up. In this case, it might be commercially viable to turn to the sea.

Choice C is absolutely irrelevant because the author narrows the ambit of his conclusion in such a way as to evade criticisms having to do with the costs of extracting from the sea:

"Therefore, until the cost of extracting uranium from seawater can somehow be reduced, this method of obtaining uranium is unlikely to be commercially viable."

Now, had the conclusion instead read:

"Therefore, this method of obtaining uranium is unlikely to be commercially viable."

then Choice C would have been very relevant in evaluating the author's argument. But with the author's conclusion, choice C is completely outside the scope.

For Okigbo: It is not that A is more relvant than C. As usual on the GMAT, there will be one and only one answer that fully satisfies the conditions of the question. (If this were not so, then the test would cease to be an objective means of evaluating test-takers!)
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by DeepakYakkundi » Wed Nov 18, 2009 11:12 pm

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After going through Testluv's reply, I agree (a) is the answer. (c) is wrong.
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