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A very tough CR-Rose beetles

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by FightWithGMAT » Tue Aug 10, 2010 8:13 am
raviagni wrote:A certain type of insect trap uses a scented lure to attract rose beetles into a plastic bag from which it is difficult for them to escape. If several of these traps are installed in a backyard garden, the number of rose beetles in the garden will be greatly reduced. If only one trap is installed, however, the number of rose beetles in the garden will actually increase.

Which one of the following, if true, most helps to resolve the apparent discrepancy?
(A) The scent of a single trap�s lure usually cannot be detected throughout a backyard garden by rose beetles.
(B) Several traps are better able to catch a large number of rose beetles than is one trap alone, since any rose beetles that evade one trap are likely to encounter another trap if there are several traps in the garden.
(C) When there are several traps in a garden, they each capture fewer rose beetles than any single trap would if it were the only trap in the garden.
(D) The presence of any traps in a backyard garden will attract more rose beetles than one trap can catch, but several traps will not attract significantly more rose beetles to a garden than one trap will.
(E) When there is only one trap in the garden, the plastic bag quickly becomes filled to capacity, allowing some rose beetles to escape.


PLZ POST WITH EXPLANATIONS
IMO D

It explains both sides of the argument. E does only half.
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by diebeatsthegmat » Wed Aug 11, 2010 1:51 am
raviagni wrote:A certain type of insect trap uses a scented lure to attract rose beetles into a plastic bag from which it is difficult for them to escape. If several of these traps are installed in a backyard garden, the number of rose beetles in the garden will be greatly reduced. If only one trap is installed, however, the number of rose beetles in the garden will actually increase.

Which one of the following, if true, most helps to resolve the apparent discrepancy?
(A) The scent of a single trap�s lure usually cannot be detected throughout a backyard garden by rose beetles.
(B) Several traps are better able to catch a large number of rose beetles than is one trap alone, since any rose beetles that evade one trap are likely to encounter another trap if there are several traps in the garden.
(C) When there are several traps in a garden, they each capture fewer rose beetles than any single trap would if it were the only trap in the garden.
(D) The presence of any traps in a backyard garden will attract more rose beetles than one trap can catch, but several traps will not attract significantly more rose beetles to a garden than one trap will.
(E) When there is only one trap in the garden, the plastic bag quickly becomes filled to capacity, allowing some rose beetles to escape.
i am stuck between D and E and i chose E because i dunot understand D so much.
on the one hand it says the presense of any traps will attract more rose bettles, it means the more trap the more roses beetles and on the other hands it states several traps will not attract more rose beetles to the garden than one tra[. is it not right that 2 sentences in that aurgument opposite each other?

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by adi_800 » Sat Aug 14, 2010 7:50 am
I too answered E but seems that E is wrong..

E says that bag becomes full early...
So lets say, there are 5 insects present n capacity is to catch 2 insects..
So, when the bag becomes over capacity by catching 5 insects, then 3 escape... But where is the increase in number of insects....
D says that more will be attracted, increasing the number of insects...
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by crackinggmat » Sat Aug 14, 2010 11:22 am
OA is D ..i googled
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by Brian@VeritasPrep » Mon Aug 23, 2010 9:49 am
Hello, everyone - sorry for the late check-in on this (I was on vacation when I received a few PMs to chime in, and didn't get those messages until today).

D is the only answer choice that is consistent with both parts of the discrepancy:

1) Several traps will greatly reduce the overall number of beetles

BUT

2) Only one trap will actually INCREASE the number of beetles

Choice E demonstrates why one trap alone may not have a proportional impact to multiple traps (some beetles will escape, so the presence of multiple traps will do a much better job than one alone), but it doesn't address that INCREASE in the overall number of beetles.

Choice D does that, by noting that the first part of the trap is to draw beetles, and the second is to trap them. With only one trap, it will draw many more than it can catch, increasing the number of beetles and only catching some of them. If other traps won't increase the number of beetles, then they'll simply catch without drawing more, so that's why multiple traps will decrease the number of beetles, but one trap alone will actually increase that number.


This question is a great example of the methodology for Strengthen/Weaken/Explain-the-Paradox questions - the specifics of the conclusion (or paradox) are paramount - here, it's crucial that the correct answer doesn't merely explain why one trap may have limited effectiveness...we need to explain that overall INCREASE in the number of beetles,and only D does that.
Brian Galvin
GMAT Instructor
Chief Academic Officer
Veritas Prep

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