Climatologist: Global warming is affecting snowfall throughout the

Question

Climatologist: Global warming is affecting snowfall throughout the state. In 2004, nearly 60% of all precipitation in our state was in the form of snow, whereas by 2009 that percentage had dropped to just 42%. At this rate, in 20-30 years the state may have no snow at all.

The climatologist’s argument depends on which of the following assumptions?

(A) The percentages he cites will continue to decrease at a linear rate.

(B) Global warming will cease to be a factor in the state’s snowfall yields over the next 20-30 years.

(C) Global warming is not the only factor affecting the state’s snowfall yields over the past decade.

(D) The amount of precipitation in the state in 2009 was not significantly greater than it had been in 2004.

(E) The volume of rainfall, the other primary form of precipitation in the state, was not higher in 2004 than it was in 2009.

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mrfrantic · Accepted Answer

Percentage decrease doesn't always mean that the overall value is decreasing.

For "At this rate" trend to be true, the absolute value of snow precipitation in 2009 should be less than in 2004, otherwise it will break the conclusion. For example, let's say there was 100mm precipitation overall in 2004. This means 60% or 60mm was in the form of snow. Now, for 2009, let's consider two cases of precipitation: 1) 150mm and 2) 75mm. In the 1st case, 42% precipitation was in snow form, which is equal to 63mm. This is greater than 60mm snow precipitation in 2004, meaning that the author's conclusion about possible no snowfall in the next 20-30 years doesn't hold true. However, in the 2nd case, snow precipitation would be ~32mm, less than in 2004. Therefore, in order to not break author's conclusion, the 2009 snow precipitation should not be significantly greater than in 2004.

Hope this is clear.

sayan640 · Answer

D should be the answer. If the base amount is significantly high then even though the percentage lowered , still we may get a good amount of snow.

Posted from my mobile device

TusharPal30 · Answer

In my opinion, the answer should be A, the author has taken 2 year data, (2004 and 2009) and calculated rate at which the precipitation is decreasing, he further says if it continues "At this rate" which means he is taking into assumption that the rate at which the snowfall precipitation will decrease will not change.

Please correct me if I am wrong

Please correct me if I am wrong

jack5397 · Answer

IMO - D

POE

(A) The percentages he cites will continue to decrease at a linear rate. - Even if it does not continue to decrease linearly still does not affect the conclusion  - Eliminate

(B) Global warming will cease to be a factor in the state’s snowfall yields over the next 20-30 years. - Irrelevant to the conclusion- Eliminate

(C) Global warming is not the only factor affecting the state’s snowfall yields over the past decade. - Conclusion is about the global warming only any alternative plan is straight away weakener for the assumption question.  - Eliminate

(D) The amount of precipitation in the state in 2009 was not significantly greater than it had been in 2004.  - Correct

(E) The volume of rainfall, the other primary form of precipitation in the state, was not higher in 2004 than it was in 2009. - We are only concerned with the snow in the question.  - Eliminate

Bunuel · Answer

Veritas Prep Official Explanation

D.

This question tests a data flaw that occurs commonly throughout the GMAT – just because the percentage that snow constitutes of the total precipitation has gone down DOES NOT mean that the actual volume of snowfall has gone down.

If overall precipitation has doubled, for example, then snowfall has gone up, from 60/100 to 84/200. D exposes this flaw – if you negate D it says “the volume of precipitation in 2009 was significantly greater than it was in 2004”, evidence that the total precipitation could well have dramatically increased.

Note the flaws in trap answers A and E – in A, the continued trend doesn’t need to be linear; in fact if it were exponential that would strengthen the conclusion even further.

And choice E actually does the opposite of D – if negated, E says “there was more rainfall in 2004 than in 2009”, showing that overall precipitation (and therefore snowfall) was way down in 2009.

tommychudw · Answer

Why not A?

The climatologist's predicted argument will hold if we consider that the percentages must decrease either linearly or exponentially.

If we don't assume accordingly and suppose a hypothetical logarithmic rate of decay for snowfall, won't the amount of snowfall tend towards but never touch zero? The climatologist's argument will then not hold in this case. Please enlighten me, thanks!

Matty101 · Answer

Bunuel  has a good explanation above, but my understanding is, while yes, if snowfall decreased at a linear rate, it could lead to 0, it certainly would not have to decrease at a linear rate. It could decrease at an exponential rate (more quickly), and the conclusion would still be true. Therefore, the suggestion that the argument assumes a linear decreases is false, because it could assume an exponential decrease.

ElenaFerrante · Answer

In my opinion, the argument states "  At this rate , in 20-30 years the state may have no snow at all." So it is part of the context / premise that the snowfall will reduce at the given rate and is not a new piece of info. that plugs a gap in the argument.

VerbalBot · Answer

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Climatologist: Global warming is affecting snowfall throughout the

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