A certain type of insect trap uses a scented lure to attract rose beet

Premise 1:- 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.
Counter Premise 2:- If only one trap is installed, however, the number of rose beetles in the garden will actually increase.
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Paradox is that a single trap will "increase" rose beetles from the current figures while more traps doesn't. The answer choice must not address only of the type of traps rather equally address both scenarios and provide an explanation direct or implied as to why the paradox exists.


(A) The scent of a single trap’s lure usually cannot be detected throughout a backyard garden by rose beetles. - This is false as if this were the case the paradox wouldn't exist.
(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. - The paradox is about rose beetles in the garden itself and not within the trap. We are not discussing the ability of 1 vs more than 1 trap to capture beetles! Incorrect.
(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. - Similar to B not discussing ability to catch beetles and it doesn't resolve the paradox.
(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. - Perfect answer. It means 1 or 2 or 3 or more , the presence of any number (at least 1 or more) will attract the same number of rose beetles which means the luring scent of whether 1 trap or more has the same effect in attracting the same number of rose beetles to the garden. This when read in conjunction with the argument clearly resolves the paradox by stating that irrespective of the number of traps the number of beetles that would be attracted into the garden will remain same, but the more the number of traps the better is it to catch more number of beetles within those traps!
(E) When there is only one trap in the garden, the plastic bag quickly becomes filled to capacity, allowing some rose beetles to escape - The same is applicable for many bangs too hence incorrect.
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Correct Answer is (D).

GMATNinja VeritasKarishma

I thought because there is only one trap in the garden it will attract more beetles but will not be able to capture all thus there is an increase in beetles compared to when there are many traps(because they attract more and can capture more).

Is my pre-thought correct? How is option D correct on these lines?? and why is E wrong??

I think your pre-thought is essentially the same thing as choice D. The single trap attracts a lot of beetles (leading to the increase) and can't catch as many as it attracts (so you get a net increase in number of beetles). But then with multiple traps the number of beetles attracted isn't substantially more, yet the number caught dramatically increases. Your thinking perfectly explains D.

The problem with E is that it doesn't account at all for the increase in beetles. It tells you that one trap has a limitation in the number of beetles it can catch, but it doesn't explain why that one trap would lead to an overall INCREASE. Note that the given information doesn't talk about attracting beetles to the garden itself, just into the plastic bag. So E saying "it can't catch every beetle (but it can still catch some)" allows for a marginal decrease in the number of beetles...it doesn't explain the actual increase.

Options D and E are super close. The only thing that differentiates E as the incorrect answer is that it is saying on the lines of a plastic bag and not the garden.

Doesn't this mean that if there are 100 rose beetles in a garden and if we have multiple traps then the no. of rose beetles will be reduced to say 50 or 60. But if there is only one catch then the no. of beetles will increase to 110 or 130.
I didnt get why are we comparing the no. of beetles when there is only one trap or several traps? It is not a relative increase

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. - WRONG. It is like C only. Not helpful.

(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. - WRONG. Cetainly possible but it doesn't explain why there is an increase in number of beetles when only one trap is installed.

(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.

Three choices look to be somewhat good enough - A, D and E.
In A, not able to detect does not mean there is an increase in number of beetle.
In E, escaping of beetles does not mean there is an increase in number of beetle.
A and E one or the other way are same in their approach and logic.

Answer D.

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