Although the pesticide TDX has been widely used by fruit growers since

Hi Shelrod,

It would be much better if you can share a bit more analysis. It would help you understand better because the more you write, the clear your thought process becomes.

Coming back to the question, the highlighted part in your analysis is incorrect. We are not really concerned whether some amount of TDX is dangerous or not. This concern might be behind the introduction of the new law. However, we are not concerned with this.

We are only concerned that the new regulation will not allow more TDX on fruits than earlier. So, if new regulations allowed 5 units of TDX on fruits, then earlier regulation must also have allowed this much TDX.

However, we are given that earlier laws did not allow any TDX, then how come the conclusion hold? The conclusion can hold only if in the earlier law, law enforcement agencies were not able to detect 5 units of TDX. IF they could not detect it, how would they stop it?

This is what option A says.

Does it help?

Thanks,
Chiranjeev
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Dear Himanshu,
I got your p.m. and I'm happy to respond. I believe you are being a bit naive about the scientific measuring process. The physical world and its details do not stop existing at the limits of science's ability to measure. There are all kinds of things in the world that we know exist, or that we suspect probably exist, but they are beyond the current ability of science & technology to measure. There are other things, at the atomic and subatomic level, that cannot be measured, not because of the limits of technology, but because of the fundamental limits of matter and energy at that level --- that gets into Quantum Mechanics, which is well beyond the level of science you need to know for the GMAT. You do need to realize, though, that "what can be measured" and "what really is" are not necessarily identical.

In this argument, the sentence, "a regulation in force since 1960 has prohibited sale of fruit on which any TDX residue can be detected" implies "can be detected, according to whatever technology they had in the 1960's." Now, maybe in the 1960's, they could detect TDX down to the very last molecule, so they would know exactly how much was there and could detect even the smallest portion. Or, maybe their means of measurement were more limited --- they could detect TDX in quantities down to some small number (say, a milligram, or a microgram), and beyond that level, they simply couldn't detect the TDX. We can only guess --- the prompt passage gives us no way to decide how much they could measure in the 1960s.

The OA, choice (A), suggest that the latter interpretation was correct. In other words, they had very limited abilities to measure TDX in the 1960's --- say, they could measure down to 1 microgram, but not less than that. Then, in the 1970s, say, they could measure much more precisely, down to the 0.001 microgram (i.e. the nanogram), and the trace allowed is, say, up to 1 microgram. Well, in the 1960s, if there was just less than a microgram, then they couldn't measure or detect that amount, and the fruit with that amount would be passable, while if there were just less than a microgram in the 1970s, then the scientist could detect it, but it would now be an allowable level of trace material, and the fruit still would be passable.

My friend, I strongly recommend that you start reading Scientific American. I think you need to beef up your understanding of how the experimental sciences operate. Reading a couple articles a week from Scientific American will be a good workout for the science passages you encounter on the GMAT RC, and they will give you the general background you need to make sense of science arguments on the GMAT CR.

Does all this make sense?
Mike
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1960 regulation - No fruit with detectable level of TDX on it can be sold.
New regulation - You can sell fruit on which trace amounts of TDX can be detected.

Then obviously, one would think that the new regulations are more lenient toward TDX and are allowing higher quantity of TDX to be present on the fruit being sold.

But the author tells us that the new regulations will NOT allow more TDX on fruit than was allowed in the 1960’s. Why? How can we say that the allowed levels on TDX have remained the same?

Because in 1960s, the techniques did not detect trace levels of TDX though the fruit still had that much TDX on it. It was just not detectable at that time.
Today's techniques detect trace levels. So the 1960 regulations today will not allow the same fruit to be sold since TDX will be detected today. The regulations are just being adjusted to allow the same fruit to be sold today (with the same TDX levels) by saying that trace levels are allowed. The new regulations are not allowing any more TDX than was already there.
Hence, option (A) makes sense.

(B) many more people today than in the 1960’s habitually purchase and eat fruit without making an effort to clean residues off the fruit

What people do is irrelevant.

(C) people today do not individually consume any more pieces of fruit, on average, than did the people in the 1960’s

What people do is irrelevant.

(D) at least a small fraction of the fruit sold each year since the early 1960’s has had on it greater levels of TDX than the regulation allows

This tells us that some fruit sellers are not following the law since 1960s. It is irrelevant. The point is how the new law is changing or not changing the allowed levels of TDX on fruit compared with the law of 1960s. Whether people are actually following the law or not is out of scope for us.

(E) the presence of TDX on fruit in greater than trace amounts has not been shown to cause any harm even to children who eat large amounts of fruit.

Impact of TDX on health is irrelevant. Our scope is only new law vs old law.

Answer (A)
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[A]
If the previous method to detect TDX was not accurate enough to detect it unless the level was say > 1%, then fruits with TDX qty of <=1% would have been sold anyway. If the new regulation allows up to 1% residue and if the new measurement techniques are accurate, then you will screen out fruits >1%, which is the same as it was in the 1960's.

Thats my reasoning ..

Down to A and D - D seems like the trick answer as it refers only to a fraction of the fruit

Will go with A
Not allow more TDX than before because the fruit with the trace amounts of TDX was being sold anyway.

My analysis : TDX used prio to 1960 , regulation banned any fruit on which TDX residue could be found .

New regulation replaces the old one saying some levels are permissible to be found on frutis .

New regulation will not all more TDX on fruits than earlier .... because TDX in small amounts is not dangerous compared to large amounts ?

However what i pre thought was incorrect answer in A ? Can you explain why ?

Hello Experts,
I am kind of confused while reviewing this question.

The Last Line says that the change will not allow more TDX on fruit than was allowed in the 1960's because...

now, Where does in the question, the author says that TDX was allowed.. Infact, it was never allowed. That is why there was a regulation that prohibits the sale of fruit.

Please explain.

Your help will be appreciated.

They are talking about the residue that was allowed in the 1960's.

1960's - No sale of fruits on which residue is detected
Now - Trace amounts are acceptable
BUT..
These trace amount should not be more than the residual amount detected in the 1960's

Thanks igotthis for the reply.

However, can you please clarify this:

Argument says that:



Isn't it mentioned that amount of TDX residue should be Zero?



This is how I interpreted the Argument:

1) You can't apply TDX because of regulation. If your fruits tested positive, you will not be allowed to sell.
2) Now you can apply TDX in limited amounts.
But
The amount of TDX cannot be more than that was allowed.

As per my analysis, if you are not allowed to apply TDX in 1960s.. then how can question stem says so..?

Where I'm going wrong. Please correct.

Im getting very confused in understanding the question itself. Can some Expert explain the argument and the solution in simple steps.

Dear Mechmeera,
My friend, this is problematic. This is a very well written GMAT Prep question, and the difficulty level of the text is typical of what you will see on the GMAT. If someone paraphrases the question for you, puts it all in simple terms, how exactly is this going to help you? You should not be asking for the GMAT level material to be brought down to a level you can understand. You should be entirely focused on how to bring your level of understand up to the level of the GMAT.

I will suggest a few resources. Here's a set of free GMAT idiom flashcards.
https://gmat.magoosh.com/flashcards/idioms
Here's a blog article you may find helpful:
https://magoosh.com/gmat/2014/how-to-imp ... bal-score/
Here's a three-month study plan for folks who want to improve their verbal:
https://magoosh.com/gmat/2012/3-month-gm ... l-focused/

I hope all this helps.
Mike
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The Complete the Argument type of question generally requires us to fill in an extra premise. The sentence that we have to complete almost always ends in the words ‘since’ or ‘because’, implying that we must find a reason to strengthen or support the conclusion. This argument also has been left incomplete with a ‘because’ just before the blank.

Let us break up the argument.
Conclusion: The change will not allow more TDX on fruit than was allowed in the 1960’s.

The information provided is as follows:
• the pesticide TDX has been widely used by fruit growers since the early 1960’s
• but a regulation in force since 1960 has prohibited sale of fruit on which any TDX residue can be detected
• That regulation is about to be replaced by one that allows sale of fruit on which trace amounts of TDX residue are detected.
We understand from the information that the pesticide TDX has been used since the 1960’s but there has been a regulation in place that prohibits the sale of fruit on which any residue of the pesticide can be ‘detected’.
The new regulation allows the sale of fruit on which trace amounts of the residue of the pesticide are detected.

One word to note here is ‘detected’. The other significant factor is the difference in the time between the two regulations. The conclusion is that the change will not allow any more TDX than the regulation in the 1960’s allowed. We are looking for the reason that conclusion is drawn. If the conclusion states that the change will not make a significant difference, it may be because there is not a great difference between the amount of TDX that could detected in the 1960’s and the trace amounts of TDX residue that can be detected now because the techniques for detection in the 1960’s were that effective, so they could detect the TDX down to the smallest amounts. Or it may be because the detection techniques were not that effective, so they could only detect quantities only down to a certain amount, which may be close to the trace amounts of residue.

Let us look at the options.
Options C and E are completely irrelevant. Option C discusses the individual consumption of fruit in the 1970’s and 1960’s; there is no information about the amount of TDX residue detected on fruit.

Option E discusses whether the amount of TDX residue on fruit is harmful to children or not. This option is also irrelevant since the argument doesn’t discuss whether the pesticide is harmful to any particular group of consumers and how harmful it is.
So, Options C and E can be eliminated.

Option B is also irrelevant. The argument doesn’t discuss how people consume the fruit and the effect of TDX on them because of their consumption habits. Therefore, Option B can also be eliminated.

The argument is about the amount of TDX that can be detected. The argument states that any fruit that was detected to have more residue of TDX than allowed by the regulation could not be sold. So, all D tells us is that there was at least a small fraction of fruit that was not sold. It does not tell us the reason that the argument concludes that the change in regulation will not allow any more residue than was allowed since the 1960’s. So, Option D also can be eliminated.

Option A is the only one that discusses techniques for detection of TDX residue, which is what the argument is about. It states that the techniques for detection prior to the 1970's could only detect amounts that were more than the trace amounts allowed by the new regulation.

Therefore, A is the most appropriate option to complete the argument.

Jayanthi Kumar.
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Hi Experts,
KarishmaB GMATNinja
Can you please help where I went wrong?

Although the pesticide TDX has been widely used by fruit growers since the early 1960’s, a regulation in force since 1960 has prohibited sale of fruit on which any TDX residue can be detected. That regulation is about to be replaced by one that allows sale of fruit on which trace amounts of TDX residue are detected. In fact, however, the change will not allow more TDX on fruit than was allowed in the 1960’s, because ______.

(A) pre-1970 techniques for detecting TDX residue could detect it only when it was present on fruit in more than the trace amounts allowed by the new regulations

Doubt 1 - If the recent regulation didn't allow the level more than was allowed in 1960's, may be the recent regulation goal is to keep the amount undetectable. Can we arrive at this conclusion from option A?
If yes, why they have changed the regulation in 1960 that prohibited sale of fruit on which any TDX residue can be detected if the amount was undetectable during 1960's by the pre-1970 techniques.
I am confused with the timeline and how change in regulation impacted the TDX level.
I want to understand the logic of this option.

Doubt 2 - This option doesn't provide any info regarding the current techniques. If the current technique can detect the level, the goal to shift to 1960's level fails.

(D) at least a small fraction of the fruit sold each year since the early 1960’s has had on it greater levels of TDX than the regulation allows
What's the impact of this statement on the argument?
How they were able to sale a fruit with greater levels of TDX than the regulation allows?. I think if some fruits with high amount of TDX go undetectable, there is no use of regulation. So no impact on the argument bcz this statement provides no reason why the current TDX level shouldn't be more than was allowed in 1960's.

Let's start by nailing down the key points of the passage:

• TDX has been used since the 1960's.
• A 1960 regulation prohibited sale of fruit on which "TDX can be detected."
• A new regulation will allow fruit on which "trace amounts of TDX" are detected.

The correct answer should explain why this change will "not allow more TDX on fruit than was allowed in the 1960's." Let's now consider (A):

Notice the 1960 regulation doesn't prohibit any TDX at all. It just prohibits sale of fruit where "TDX can be detected." So if the pre-1970 technique was not sensitive enough to detect "trace amounts," then the old law actually ALLOWED trace amounts of TDX. Because the only law only prohibited amounts of TDX that could be detected back then.

This would explain why the new regulation will "not allow more TDX on fruit than was allowed in the 1960's." Because according to (A), trace amounts were allowed in the 1960's (since the pre-1970 test used then couldn't actually detect trace amounts). So even though the new regulation allows "trace amounts," it won't allow MORE than was allowed in the 1960 regulation (which also allowed trace amounts).

Since (A) gives us the explanation we want, it's correct.

Let's now analyze (D):

According to (D), even though a 1960 regulation was in place, it wasn't always followed properly. In other words, despite the regulation, fruit on which TDX could be detected was sold.

How could this happen? Unfortunately, the passage doesn't really explain this. Maybe one of the regulators did a bad job? Maybe the testing equipment broke one day? All we know is that the 1960 regulation was occasionally broken. So how does this impact the passage?

As you suggest, it fails to explain why the new regulation won't allow more TDX than was allowed in the 1960's. To summarize -- the new law will allow trace amounts of TDX on fruit. The old law only allowed fruit where no TDX could be detected. Since (D) doesn't explain this apparent discrepancy, we can discard it.

I hope that helps!
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This is what we know:
- old regulation in force (since 1960) prohibited the sale of fruit on which any TDX residue could be detected
- new regulation will allow the sale of fruit on which trace amounts of TDX residue are detected
- In fact, the change will not allow more TDX on fruit than was allowed in the 1960 because ....

We have to fill in what comes after the because. So the question we have to answer is, HOW is this possible?
This is a "resolve the paradox" question.

I'm stating the paradox one more time:
On the one hand, the 1960s regulation prohibited the sale of fruit on which any TDX was detected.
On the other hand, the new regulation allows the sale of fruit with trace amounts of TDX.
Paradox: the amount of TDX on the fruit will stay the same.

Answer choice A gives us the resolution: 1960s technology could not detect trace amounts of TDX.

Trace amounts of TDX could have always been present, present but not detected. Allowing trace amounts of TDX will not increase the amount of TDX on fruit.

Posted from my mobile device
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The argument discusses a regulation that prohibited the sale of fruit with any detectable residue of the pesticide TDX. The regulation is about to be replaced with a new one that allows the sale of fruit with trace amounts of TDX residue. The question asks us to select the option that best completes the argument based on the information provided.

To identify the correct answer, let's consider the reasoning in the argument. The argument states that although the new regulation allows trace amounts of TDX residue, it does not actually permit more TDX on fruit than what was allowed in the 1960s. We need to find the option that logically explains why the change in regulation does not result in increased TDX levels on fruit.

Option (A) explains that the pre-1970 techniques for detecting TDX residue could only detect it when it was present on fruit in amounts greater than the trace amounts allowed by the new regulations. This means that even though the new regulations permit trace amounts, the older detection methods would not have detected such minimal levels. Option (A) logically completes the argument by providing a reason why the change in regulation does not lead to increased TDX levels on fruit.

Option (B) introduces the fact that many people today do not make an effort to clean residues off the fruit they consume. However, this information does not directly explain why the change in regulation does not allow more TDX on fruit than in the 1960s. Thus, option (B) is not the most appropriate completion for the argument.

Option (C) mentions that people today do not individually consume more pieces of fruit, on average, than people in the 1960s. While this information might be relevant in certain contexts, it does not directly address the issue of TDX levels on fruit and the change in regulation. Therefore, option (C) does not logically complete the argument.

Option (D) states that a small fraction of the fruit sold since the 1960s has had higher levels of TDX than allowed by the regulation. This information does not provide a reason why the change in regulation does not permit more TDX on fruit. Hence, option (D) is not the most suitable completion for the argument.

Option (E) suggests that the presence of TDX in amounts greater than trace levels has not been shown to cause harm, even in children who consume large amounts of fruit. While this information may be relevant to the safety of consuming TDX-contaminated fruit, it does not directly explain why the change in regulation does not result in increased TDX levels on fruit. Thus, option (E) is not the best completion for the argument.

In conclusion, option (A) logically completes the argument by providing a valid reason why the change in regulation does not allow more TDX on fruit than what was permitted in the 1960s.