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# Recently an unusually high number of dolphins have been foun

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Recently an unusually high number of dolphins have been foun [#permalink]  16 May 2016, 23:10
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61% (01:12) correct 38% (01:25) wrong based on 34 sessions
Recently an unusually high number of dolphins have been found dead of infectious diseases, and most of these had abnormally high tissue concentrations of certain compounds that, even in low concentrations, reduce dolphins’ resistance to infection. The only source of these compounds in the dolphins’ environment is boat paint. Therefore, since dolphins rid their bodies of the compounds rapidly once exposure ceases, their mortality rate should decline rapidly if such boat paints are banned.

Which of the following, if true, most strengthens the argument?

A- The levels of the compounds typically used in boat paints today are lower than they were in boat paints manufactured a decade ago.
B- In high concentrations, the compounds are toxic to many types of marine animals.
C- The compounds break down into harmless substances after a few months of exposure to water or air.
D- High tissue levels of the compounds have recently been found in some marine animals, but there is no record of any of those animals dying in unusually large numbers recently.
E- The compounds do not leach out of the boat paint if the paint is applied exactly in accordance with the manufacturer’s directions.
[Reveal] Spoiler: OA
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Re: Recently an unusually high number of dolphins have been foun [#permalink]  17 May 2016, 08:10
Expert's post
Please follow the rules for posting: using the tags to identify properly every question. This way you will help a lot future students

This is a strengthen question, according to our question stem. That say, you need to find an answer choice hat reinforce the conclusion. And confirm what our argument are saying.

This is our conclusion in the argument above

Quote:
Therefore, since dolphins rid their bodies of the compounds rapidly once exposure ceases, their mortality rate should decline rapidly if such boat paints are banned.

We must find the answers that make this statement stronger. You can follow mainly 2 strategies: or POE or pre-thinking reading the argument itself.

A- The levels of the compounds typically used in boat paints today are lower than they were in boat paints manufactured a decade ago.

A comparison between two eras f production is out of scope

B- In high concentrations, the compounds are toxic to many types of marine animals.

This is a generalization about most of the marine animals

C- The compounds break down into harmless substances after a few months of exposure to water or air.

This is the right answer: the water in which the compound is present, break down after a certain amount of time. As such, the dolphins are not in contact with the substance. Hence, they are not affected

D- High tissue levels of the compounds have recently been found in some marine animals, but there is no record of any of those animals dying in unusually large numbers recently.

Again: a comparison and its concentration in different animals it is not in our argument

E- The compounds do not leach out of the boat paint if the paint is applied exactly in accordance with the manufacturer’s directions.

The process through wich the paint is well fixed to the boats by manufacturers are not in our argument

Do not hesitate to ask if something is unclear
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Re: Recently an unusually high number of dolphins have been foun [#permalink]  18 May 2016, 00:39
This is a tough question. Here is my thinking.

The argument says that by constantly exposing the boat paint is reducing dolphins resistance to infections and they eventually die. If the compounds were to break down into harmless substances after a few months of exposure to water or air (Answer Choice C) and exposure to new boat paint is stopped through banning boat paint (the conclusion), the dolphins will increase their resistance to infections, and deaths will eventually decline.
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Re: Recently an unusually high number of dolphins have been foun [#permalink]  17 Nov 2016, 22:41
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Recently an unusually high number of dolphins have been found dead of infectious diseases, and most of these had abnormally high tissue concentrations of certain compounds that, even in low concentrations, reduce dolphins’ resistance to infection. The only source of these compounds in the dolphins’ environment is boat paint. Therefore, since dolphins rid their bodies of the compounds rapidly once exposure ceases, their mortality rate should decline rapidly if such boat paints are banned.

Which of the following, if true, most strengthens the argument?

A) The levels of the compounds typically used in boat paints today are lower than they were in boat paints manufactured a decade ago.
B) In high concentrations, the compounds are toxic to many types of marine animals.
C) The compounds break down into harmless substances after a few months of exposure to water or air.
D) High tissue levels of the compounds have recently been found in some marine animals, but there is no record of any of those animals dying in unusually large numbers recently.
E) The compounds do not leach out of the boat paint if the paint is applied exactly in accordance with the manufacturer’s directions.

Another way to think of a strengthen question is: which answer, if I were to weaken it, would thus weaken the conclusion?

Choice C is the correct answer because the only way banning such boat paint will work is if the boat paint already floating around were to become less toxic to the dolphins over time. This is what's known as a "Cause and Effect" assumption.

The 5 main types of assumptions (CCRIQ*)

C = Cause and Effect (or Correlation and Causation)
C = Comparison and Analogy
R = Representativeness
I = Implementation
Q = Questionable Evidence / Quantitative Methods

*(from "Ace the GMAT" by Brandon Royal)

Keep in mind that any strengthen/weaken answer choice can be evaluated by how directly relevant it is to the conclusion itself.

A) Who cares about 10 years ago? The conclusion is about the future.
B) The conclusion pertains to dolphins, not other marine mammals.
D) Again "marine animals" are not the same as dolphins.
E) The problem already exists, so clearly this is not relevant. Similar to Choice A.

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Last edited by skypetutor on 21 Mar 2018, 18:50, edited 8 times in total.
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Re: Recently an unusually high number of dolphins have been foun [#permalink]  19 Jan 2017, 20:15
Hello Everyone,

Correct me if I am wrong that is, if the compound breaks down into harmless substances then their is no need to ban it as specified in the last sentence. If we think like that it will only weaken the argument not strengthen it....
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Re: Recently an unusually high number of dolphins have been foun [#permalink]  21 Jan 2017, 08:34
Expert's post
PMirdha wrote:
Hello Everyone,

Correct me if I am wrong that is, if the compound breaks down into harmless substances then their is no need to ban it as specified in the last sentence. If we think like that it will only weaken the argument not strengthen it....

The ban is important because in few years the boat paint of THOSE existed BEFORE the ban depletes in few years. If this happens BUT we do not ban the boats and their paints, we will end up in a spiral endless.

I.E: we have 10 boats and from now they are banned. In one year the compound is dissolved and dolphins gain numbers. BUT if the boats are not banned even if the compound depletes we will have alway it because new boats will introduce it once gain because NOT banned.

Hope this helps
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Re: Recently an unusually high number of dolphins have been foun [#permalink]  22 Jan 2019, 11:51
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I think this is a confusing and tricky one. I have gone through the explanations and no matter how much I would have thought about it, I would have still chosen B. The argument is that banning boat pain will reduce Dolphin death. It is very hard to understand how option C supports that argument.
Re: Recently an unusually high number of dolphins have been foun   [#permalink] 22 Jan 2019, 11:51
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