Inference or main point??

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Inference or main point??

by reply2spg » Sun Aug 15, 2010 2:09 pm
Though question stem says main point question, I feel this is inference question

A report on the likely effects of current levels of air pollutions on forest growth in North America concluded that, since nitrogen is necessary nutrient for optimal plant growth, the nitrogen deposited on forest soil as result of air pollution probably benefits eastern forests. However, European soil scientists have found that in forests saturated with sulfate and nitrate, tress begin to die when the nitrogen deposited exceeds the amount of nitrogen absorbed by the forest system. Since this finding is likely to apply to forests everywhere, large areas of eastern forests of North America are, undoubtedly, already being affected adversely.

Which one of the following most accurately expresses the main point of the passage?

(A) The implication of the report cited is that the amount of nitrogen reaching eastern forests by way of polluted air is approximately what those forests need for optimal growth.

(B) If large areas of eastern forests were increasingly saturated with sulfate and nitrate, the capacity of those forest systems for absorbing nitrogen would also increase.

(C) The type of analysis used by European soil scientists does not necessarily apply to eastern forests of North America.

(D) The eastern forests are the only forests of North America currently affected by polluted air.

(E) Contrary to the report cited, the nitrogen pollution now in the air is more likely to cause trees to die in eastern forests than to benefit them.

OA Later
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by grockit_andrea » Sun Aug 15, 2010 4:50 pm
The approach to a main point question is often very similar to that used for an inference question, and you're right that here the correct answer could be termed either an inference or a main point. That's because the argument already has a conclusion, which is the same thing as the main point. Since an inference question is something that must be directly supported by the text, the rephrased main point/conclusion could also be a valid inference. However, what you should remember is that, although the main point could be an inference, if this question had actually asked for an inference, there could have been many other valid inferences besides this one.
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by debmalya_dutta » Sun Aug 15, 2010 5:09 pm
OA please . My pick is E
reply2spg wrote:Though question stem says main point question, I feel this is inference question

A report on the likely effects of current levels of air pollutions on forest growth in North America concluded that, since nitrogen is necessary nutrient for optimal plant growth, the nitrogen deposited on forest soil as result of air pollution probably benefits eastern forests. However, European soil scientists have found that in forests saturated with sulfate and nitrate, tress begin to die when the nitrogen deposited exceeds the amount of nitrogen absorbed by the forest system. Since this finding is likely to apply to forests everywhere, large areas of eastern forests of North America are, undoubtedly, already being affected adversely.

Which one of the following most accurately expresses the main point of the passage?

(A) The implication of the report cited is that the amount of nitrogen reaching eastern forests by way of polluted air is approximately what those forests need for optimal growth.
the stimulus states "large areas of eastern forests of North America are, undoubtedly, already being affected adversely". So the amount is more that that required for optimum growth

(B) If large areas of eastern forests were increasingly saturated with sulfate and nitrate, the capacity of those forest systems for absorbing nitrogen would also increase.
Not mentioned in the passage

(C) The type of analysis used by European soil scientists does not necessarily apply to eastern forests of North America.
contrary to what is stated in the passage

(D) The eastern forests are the only forests of North America currently affected by polluted air.
not mentioned in the passage

(E) Contrary to the report cited, the nitrogen pollution now in the air is more likely to cause trees to die in eastern forests than to benefit them.

OA Later
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by Prashantbhardwaj » Mon Aug 16, 2010 8:51 am
Which one of the following most accurately expresses the main point of the passage?

(B) If large areas of eastern forests were increasingly saturated with sulfate and nitrate, the capacity of those forest systems for absorbing nitrogen would also increase.

It is opposite to what european theory states.

(C) The type of analysis used by European soil scientists does not necessarily apply to eastern forests of North America.

Not stated in the passage nor can it be inferred or assumed.

(D) The eastern forests are the only forests of North America currently affected by polluted air.

Not mentioned in the passage

(E) Contrary to the report cited, the nitrogen pollution now in the air is more likely to cause trees to die in eastern forests than to benefit them.

This is based on the damage theorized in Europe which is in turn based on the fact that soils have to be already saturated with Sulphates and Nitrates which is not given for Eastern Forests.



(A) The implication of the report cited is that the amount of nitrogen reaching eastern forests by way of polluted air is approximately what those forests need for optimal growth.

Both the reports actually support this view. The American supports it directly and the european supports it indirectly. europeans support it by saying that IF the soil is already saturated by sulphates and NITRATES then additional nitrogen deposit will kill the forest trees, so if the soils of eastern forest are not saturated then it is beneficial for the forest to get additional nitrogen deposits.

Therefore my Answer is A.

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by FightWithGMAT » Wed Aug 18, 2010 8:25 am
reply2spg wrote:Though question stem says main point question, I feel this is inference question

A report on the likely effects of current levels of air pollutions on forest growth in North America concluded that, since nitrogen is necessary nutrient for optimal plant growth, the nitrogen deposited on forest soil as result of air pollution probably benefits eastern forests. However, European soil scientists have found that in forests saturated with sulfate and nitrate, tress begin to die when the nitrogen deposited exceeds the amount of nitrogen absorbed by the forest system. Since this finding is likely to apply to forests everywhere, large areas of eastern forests of North America are, undoubtedly, already being affected adversely.

Which one of the following most accurately expresses the main point of the passage?

(A) The implication of the report cited is that the amount of nitrogen reaching eastern forests by way of polluted air is approximately what those forests need for optimal growth.

(B) If large areas of eastern forests were increasingly saturated with sulfate and nitrate, the capacity of those forest systems for absorbing nitrogen would also increase.

(C) The type of analysis used by European soil scientists does not necessarily apply to eastern forests of North America.

(D) The eastern forests are the only forests of North America currently affected by polluted air.

(E) Contrary to the report cited, the nitrogen pollution now in the air is more likely to cause trees to die in eastern forests than to benefit them.

OA Later
IMO A

E does not pass the fact test.

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by hero » Wed Aug 18, 2010 8:55 am
A says that the pollution is "approximately what is needed for optimal growth". But the argument states that nitrogen is A necessary nutrient for optimal plant growth. I feel answer A is exaggerated just enough to be incorrect.

E on the other hand i do see as passing the fact test. We take all the information in the argument as true, whether you agree with it or not. so the correct answer must support what is true in the argument. the last sentence states that "eastern forests of North America are, UNDOUBTEDLY, already being affected ADVERSELY."

Also note that the argument starts with "a report on", but is soon countered by the author's main point: a counter to the first statement. He introduces this with "however, ...."

so the main point isn't about the benefits of pollution on forests, it's about the consequences.

E.

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by SeemaSkl » Wed Aug 18, 2010 9:27 am
IMO it's E.

The obvious inference according to me is that eastern forests are already saturated with nitrogen. That is why author makes the conclusion that the trees in these forests are being affected adversely.

Actually, I initially thought it's A until I realized I missed the word 'approximately'. If we substitute 'approximately' with 'more than', A will be the better answer than E. This was a trap for me.

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by kvcpk » Wed Aug 18, 2010 10:15 am
The question is asking for the main point and not the inference.
IMO E. Because it explains the intended conclusion of the author.

A is just a paraphrased version of a premise and hence cant be the main point of the passage.

Let me know your thoughts.!!
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by pnk » Wed Aug 18, 2010 10:35 am
reply2spg wrote:Though question stem says main point question, I feel this is inference question

A report on the likely effects of current levels of air pollutions on forest growth in North America concluded that, since nitrogen is necessary nutrient for optimal plant growth, the nitrogen deposited on forest soil as result of air pollution probably benefits eastern forests. However, European soil scientists have found that in forests saturated with sulfate and nitrate, tress begin to die when the nitrogen deposited exceeds the amount of nitrogen absorbed by the forest system. Since this finding is likely to apply to forests everywhere, large areas of eastern forests of North America are, undoubtedly, already being affected adversely.

Which one of the following most accurately expresses the main point of the passage?

(A) The implication of the report cited is that the amount of nitrogen reaching eastern forests by way of polluted air is approximately what those forests need for optimal growth.

(E) Contrary to the report cited, the nitrogen pollution now in the air is more likely to cause trees to die in eastern forests than to benefit them.

OA Later
A - is not the answer in either inference or main point question. A says, 'amount of nitrogen reaching eastern forests is optimal for forests' - If that were the case, the last sentence of the argument would not have said "eastern forests being affected adversely."

I was debating btn D and E - D dropped because 'its too strong' and nowhere in argument we get a feel that eastern forests are the only affected ones...though argument talks only about 'eastern forests'

B - dropped bcoz it tries to show a causal relationship

IMO E

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by hero » Wed Aug 18, 2010 10:37 am
kvcpk wrote:The question is asking for the main point and not the inference.
IMO E. Because it explains the intended conclusion of the author.

A is just a paraphrased version of a premise and hence cant be the main point of the passage.

Let me know your thoughts.!!
good point also. if it were an inference ( otherwise known as a Must Be True ) question, paraphrasing would be a correct option. but in a main point, the correct answer must be true AND convey the main point of the author's argument.

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by diebeatsthegmat » Thu Aug 19, 2010 12:13 pm
reply2spg wrote:Though question stem says main point question, I feel this is inference question

A report on the likely effects of current levels of air pollutions on forest growth in North America concluded that, since nitrogen is necessary nutrient for optimal plant growth, the nitrogen deposited on forest soil as result of air pollution probably benefits eastern forests. However, European soil scientists have found that in forests saturated with sulfate and nitrate, tress begin to die when the nitrogen deposited exceeds the amount of nitrogen absorbed by the forest system. Since this finding is likely to apply to forests everywhere, large areas of eastern forests of North America are, undoubtedly, already being affected adversely.

Which one of the following most accurately expresses the main point of the passage?

(A) The implication of the report cited is that the amount of nitrogen reaching eastern forests by way of polluted air is approximately what those forests need for optimal growth.

(B) If large areas of eastern forests were increasingly saturated with sulfate and nitrate, the capacity of those forest systems for absorbing nitrogen would also increase.

(C) The type of analysis used by European soil scientists does not necessarily apply to eastern forests of North America.

(D) The eastern forests are the only forests of North America currently affected by polluted air.

(E) Contrary to the report cited, the nitrogen pollution now in the air is more likely to cause trees to die in eastern forests than to benefit them.

OA Later
is E the OA

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by FightWithGMAT » Fri Aug 20, 2010 12:34 am
FightWithGMAT wrote:
reply2spg wrote:Though question stem says main point question, I feel this is inference question

A report on the likely effects of current levels of air pollutions on forest growth in North America concluded that, since nitrogen is necessary nutrient for optimal plant growth, the nitrogen deposited on forest soil as result of air pollution probably benefits eastern forests. However, European soil scientists have found that in forests saturated with sulfate and nitrate, tress begin to die when the nitrogen deposited exceeds the amount of nitrogen absorbed by the forest system. Since this finding is likely to apply to forests everywhere, large areas of eastern forests of North America are, undoubtedly, already being affected adversely.

Which one of the following most accurately expresses the main point of the passage?

(A) The implication of the report cited is that the amount of nitrogen reaching eastern forests by way of polluted air is approximately what those forests need for optimal growth.

(B) If large areas of eastern forests were increasingly saturated with sulfate and nitrate, the capacity of those forest systems for absorbing nitrogen would also increase.

(C) The type of analysis used by European soil scientists does not necessarily apply to eastern forests of North America.

(D) The eastern forests are the only forests of North America currently affected by polluted air.

(E) Contrary to the report cited, the nitrogen pollution now in the air is more likely to cause trees to die in eastern forests than to benefit them.

OA Later
IMO A

E does not pass the fact test.
If OA is E, I would be surprised :(

No where in the passage it is mentioned that eastern forests of the US have reached the saturation level of nitrogen deposits.

The report published for eastern forests does not reveal that the nitrogen is more than what the tress can consume. They do not even publish any bad consequence of nitrogen deposits in eastern forests. So as per this report till now everything is good in eastern forests (situation is under control in terms of nitrogen level).

The European study says that the forest with saturated level of nitrogen in the form of Nitrate and Sulfate could produce adverse effect on these forest. Though they speculate that eastern forests are badly affected, but these scientist do not exactly know whether eastern forests have saturated with Nitrogen. Which is not teh case actually, as per the first report.

Another implication of the European study is that IF forests are NOT saturated, it is less likely that they are affected negatively. So actually this implication gives an idea that the eastern forests are at good level of nitrogen and would not get affected negatively.

I want to see the OA

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by norizam » Tue Aug 31, 2010 12:32 am
reply2spg wrote:Though question stem says main point question, I feel this is inference question

A report on the likely effects of current levels of air pollutions on forest growth in North America concluded that, since nitrogen is necessary nutrient for optimal plant growth, the nitrogen deposited on forest soil as result of air pollution probably benefits eastern forests. However, European soil scientists have found that in forests saturated with sulfate and nitrate, tress begin to die when the nitrogen deposited exceeds the amount of nitrogen absorbed by the forest system. Since this finding is likely to apply to forests everywhere, large areas of eastern forests of North America are, undoubtedly, already being affected adversely.

Which one of the following most accurately expresses the main point of the passage?

(A) The implication of the report cited is that the amount of nitrogen reaching eastern forests by way of polluted air is approximately what those forests need for optimal growth.

(B) If large areas of eastern forests were increasingly saturated with sulfate and nitrate, the capacity of those forest systems for absorbing nitrogen would also increase.

(C) The type of analysis used by European soil scientists does not necessarily apply to eastern forests of North America.

(D) The eastern forests are the only forests of North America currently affected by polluted air.

(E) Contrary to the report cited, the nitrogen pollution now in the air is more likely to cause trees to die in eastern forests than to benefit them.

OA Later
The red part of the argument is just some claims, something to introduce the subject matter. In CR Bible, it is explained under "some says....OR It was believed...and so on". We can almost safely ignore it. The real argument is indicated by the word "however"; this word signals the change in direction and also signals the start of the author's real argument. The author is just saying that too much nitrogen has an adverse affect on the trees; instead of making the trees healthier, it ends up killing them. So E fits the bill.

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by David@VeritasPrep » Tue Aug 31, 2010 6:30 am
Norizam -

Very nice point. I make sure to point out to my students that whatever comes before the strong transition, (such as "however, but, it cannot be true, yet") CANNOT be the main conclusion. I no that we should never say never, but if the argument says "Some people believe x BUT..." then you know that x is not the conclusion! It is something that is mentioned in order to knock it down - called a "straw man."

For example, I might say, "some people say that you should approach Reading Comp this way, others say do this, BUT in reality you should..."well you know that the first two techniques will not be the main conclusion.

This hard transition happens frequently on the GMAT...watch for something similar in reading comprehension!

By the way, E is certainly the main point. This is very similar to an inference question, but just remember what Andrea said earlier, there is really only one good answer to a main point, but there are many possible inferences.
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by ankurmit » Tue Aug 31, 2010 11:43 pm
IMO E
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