In the past year, there has been a dramatic increase in the number of

Question

In the past year, there has been a dramatic increase in the number of people killed by alligators in Florida. During this same time, there has been an increase in the development of new houses, golf courses, and shopping areas in former wilderness areas within the state. Therefore, the increase in fatal alligator attacks must have been caused by the increase in the number of humans living in the alligator’s habitat.

Which of the following, if true, most seriously calls into question the explanation above?

A. Two years ago, a government initiative to reduce the alligator population size by destroying alligator eggs ended.
 
B. An increase in fatal alligator attacks tends to make people more cautious around lakes, ponds, swamps and canals.

C. The number of people killed by snake bites, spider bites and scorpion stings in Florida has held steady for many years.

D. Many of the new state residents have moved to newly constructed areas near water that is suitable for habitation by alligators.

E. The undeveloped areas of Florida have decreased in area by 5% in the past year.

abhijit_sen · Answer

IMO C.
Wildrness holds Snakes, Spiders, and Scorpions in addtion to alligator. If attacks from alligator is rising then attacks from these animals should rise proportionately. But as C says, attacks from this animals not rising. So weakens the case.

x97agarwal · Answer

POE gives me C. IMO C

All others A, B, D, E strengthen the conclusion. However, I have no good explanation why C might be correct.

pmenon · Answer

i would say A for this one actually; we have to attack the conclusion that more attacks have been due to people moving into alligators habitat. To me, I interpreted A as saying that if the eggs are no longer destroyed, you could have an increased population, which thereby could result in the increase in number of attacks

gmatnub · Answer

Since you 2 are gmat heavyweights, I will just go ahead and give the OA, it is A.

C is not correct because Spiders, and Scorpions attacks are usually not FATAL, and snake bites are fatal, but only when go untreated. Whereas attacks by grown alligators are usually fatal (if you can't escape).

This is where MGMAT messed up. They gave A as the OA, but it can't be true either, because we all know that 2 years old alligator can't fatally injury people, not even babies, because their jaws are not big/strong enough to kill a baby, let alone toddlers or grown up. The babies can die from unmonitored bleeding, but how likely is that?

x97agarwal · Answer

I understand your explanation, however, maybe the Q is structured worng and is debateable. Normally in CR you cannot bring too extreme external assumptions into play.

Thanks.

FN · Answer

i went for A as well..

A gives an alternative reason..maybe now that eggs are not being destroyed there are more alligators thus more attacks..

gmatnub · Answer

That is my point, 2 years old alligators can not kill people. All that will happen in A is that you would have a bunch of yearling alligators around, which are harmless to people, or at least can not deal fatal attacks.

humtum0 · Answer

A is best among all the ans. choices

joshnsit · Answer

Guys, how does E strengthen the argument?
If the undeveloped areas of Florida decreases in area by 5% in the past year, then alligator population should also decrease. And so will decrease their attacks. Shouldn't it be so?

nechets · Answer

Hi Joshnsit - I think that your flow of reasoning is somehow compelling, but the most importnat thing in a weaken question is to focus on conclusion. The conclusion for this argument states that the increase in alligator attacks is caused by humans living in the animal's habitat. Therefore, I suppose that a decrease in undeveloped areas means more humans living in the animal's habitat.

I hope it helps,

joshnsit · Answer

nechets, I understand where you are coming from. 
X= increase in the number of humans living in the alligator’s habitat. 
Y = increase in fatal alligator attacks
The causality conclusion says: X ---Causes---> Y -----------(1)

If any another Cause X causes Y, then as per alternate causation theory, conclusion weakens.
Choice A says "a government initiative" ----Causes---->Y. Therefore it weakens causality conclusion in (1)
I agree with it. It completely fits the bill.

Another ways to weaken causality, as per CR Bible, are :
1) Prove that X happen when Y dont happen
2) Prove that Y happen when X dont happen
3) Prove that Y is causing X
4) Prove that there is some statistical issues

Now, Choice E says "Decrease in alligator attacks" is happening. This should weaken Y. In a weaken question, one has a right to attack premises(Y to be specific), and I tried doing that. This is an MGMAT problem and I am getting so many dubious/detracting choices which are hard to eliminate as per CR rules.

But what I am more concerned is that this choice has been told as a strengthener in their analysis and it is opposite of what was deciphered by me. So, any ideas in what sense can E become a strengthener.

semwal · Answer

CONCLUSION- increase in the number of humans living in the alligator’s habitat-----LEADS TO ----- increase in fatal alligator attacks.

"A" correctly brings out   --------INCREASE IN NUMBER OF ALLIGATORS --- leads to------ INCREASE IN FATAL ALLIGATOR ATTACKS... /b]

" E" just mentions what is already in the premise.....We know that human habitat is extending to undeveloped areas... ONLY a 5% factor has been added. ....... How can merely repeating a premise strengthen or weaken an argument ? " E" , therefore , makes no difference...................

kudos if you please.......

joshnsit · Answer

semwal ji, You rock.. Your statement about E finally dawned enlightenment on troublesome me on this question. E actually supports the fact X(increase in the number of humans living in the alligator’s habitat). And I think this is what MGMAT suggests when they say E as supporter.
X= increase in the number of humans living in the alligator’s habitat.
Y = increase in fatal alligator attacks
The causality conclusion says: X ---Causes---> Y -----------(1)

Still, I didn't like the choice E as E supports premise X and destroys premise Y(because it indicate reduction in number of alligators in another sense) at the same time. But, I agree that causal conclusion weakener choice A is way better than E.

semwal · Answer

DEAR JOSHNSIT,

The only issue with "A" is that we have to extend our imagination.... since destruction of eggs has ended.... more baby alligators   MAY    be taking birth.... this   MAY   be leading to extended population which   MAY   be leading to more fatal attacks on humans.....
however, increasing population may be leading to extension in inhabited areas.... and this itself, in first place, could have been the reason for destruction of eggs which has been stopped now.....therefore, this is a strong option....

kudos if you please......

a13ssandra · Answer

A for me too.

I think B&D strengthen and C&E are out of scope

VijayShanker · Answer

OA is A

We need to provide another reason to weaken the argument.

The number of people killed by alligators may have increased in the past year for some reason other than the increase in the number of humans living in the alligator’s habitat.

(A)  This statement properly identifies an alternative rationale (there are more alligators now) and undermines the given explanation.

However,

(C) This point about differing types of harmful wildlife is irrelevant to the argument about alligator fatalities.

sumisachan · Answer

I would go for A.

A weakens the conclusion by providing another reason for the increase in fatal deaths by alligators because the  government initiative to reduce the alligator population size by destroying alligator eggs ended .

ravi546 · Answer

The word "ended" means "stopped abruptly" or "completed"? Because, if you consider the latter, then it will mess up the reasoning.

harsh778 · Answer

I would not agree with your point. Saying this means strengthening the conclusion.

In the past year, there has been a dramatic increase in the number of

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In the past year, there has been a dramatic increase in the number of

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