The traditional treatment of strep infections has been a

E. People stop taking their antibiotic because they feel better. The problem with the traditional 7-day cycle is that people feel better sooner than they are fully cured. The wider the gap between feeling better than actually being better the larger the chances of reinfection. With the new 3-day antibiotic, theoretically, feel better time = actual cure time, narrowing the before mentioned gap and reducing reinfection.

C doesn't make sense to me. The passage is talking about strep, so the discussion about other kinds of bacterial infection is irrelevant.

Let's break this problem down. Some explanations in this forum focus exclusively on how to answer specific, isolated questions. But remember: the GMAT is a critical-thinking test. For those of you studying for the GMAT, you will want to internalize strategies that help you to identify and solve entire classes of questions. Pattern recognition is key. The tactics I will show you here will be useful for numerous questions, not just this one. This solution is going to walk through not just what the answer is, but how to strategically think about it. Here is the full "GMAT Jujitsu" for this question:

This question is clearly a "Strengthen" question, given the question stem. With strengthen questions, your job is to identify the conclusion and then look for the logical gap between the conclusion and the facts upon which that question relies. The conclusion is also clearly identified with the leverage word "Therefore..." (see the last sentence.) The overarching structure of the argument is simple: reinfection happens with a "seven-day" antibiotic because many people stop after three days of taking that drug. A new antibiotic is a "three-day" antibiotic. Therefore (in theory), reinfection will occur less often if patients use the antibiotic with the shorter prescribed course. However, you might wonder: just because people stop taking penicillin or erythromycin after three days (four days shorter than they should, resulting in reinfection), this doesn't prove that people will take the new antibiotic for three days. We make an unjustified assumption (an "Overgeneralization") when we think that people will use one drug in the same way that they would use another drug.

We need to find the answer that explains why someone will take the "three-day" antibiotic for its fully-prescribed period, while people seem to ignore the "fully-prescribed" period for penicillin or erythromycin. Any answer that doesn't help us repair this logical gap can't be the right answer. Let's look at each answer:

Some people argue that "A" is outside the scope of the argument, but it isn't necessarily. Think about it... being allergic to a drug could be a good reason why you stop taking a drug early. And yet, in order for this answer to work, we have to insert a major, unjustified assumption: that people allergic to either drug still continue to take the drug for three days, regardless of the reaction (thus completing the prescribed course of one drug, while not completing the prescribed course of another.) There is no evidence of this, so we can look for a stronger answer.

If the costs are the same for an entire "course of treatment", then there is no explicit reason why someone would stop early. This doesn't focus on the logical gap.

This answer is truly outside the scope of the argument. The argument talks specifically about the "treatment of strep infections", so this answer is baiting you into focusing on something outside of the argument. Anything that doesn't "mind the gap" in the logic is a distracting detour. It doesn't matter whether the new antibiotic cures anything else, tastes like gummy bears, or is recommended by 9/10 dentists. If the answer doesn't explain why a three-day regimen is better at reducing reinfection rates for strep infections, it is irrelevant. I call these type of trap answers "Distracting Detours" in my classes.

Answer choice "D" contains a trap similar to the issue in "C". Just because some physicians have prescribed the new antibiotic doesn't mean that it is better at reducing reinfection rates. This question is a classic "expert trap", where an answer choice defers to expert opinion without saying why the experts did what they did.

"E" gives a reason for why people stop taking the drug after three days: they "feel" better. "Feeling" better doesn't mean they are not at a risk of reinfection, nor is it equivalent with "cured." On the GMAT, it is dangerous to conflate terms that aren't truly synonymous. Someone can have reduced symptoms and still be prone to reinfection. The problem clearly states that reinfection is common because "many people stop taking those drugs" early. And "E" gives a reason for why people stop after three days. For penicillin or erythromycin, three days is insufficient. For the new antibiotic, three days is recommended. Answer choice "E" is the best answer.

However, "E" is not a perfect answer. It is still possible that the new antibiotic is not as effective or could have a higher rate of reinfection, even after the entire prescribed course is taken. But we don't need to find the answer that perfectly plugs every logical hole. We just need the one that "minds the gap" the best. Just look at the way the question is worded: it asks for an answer that "most strengthens" the argument. Four of our answer choices either are irrelevant, bait you into thinking about criteria outside of the argument, or require major additional assumptions to make work. In other words, they don't focus on fixing the logical gap. Answer choice "E" is the only one that nudges us in the right direction. I like to call these type of answer choices "Directional Nudges" in my classes. We see this pattern pretty often on the GMAT.

What we need here is something that ensures that patients will not stop taking the new medicines before 3 days are over. Lets analyze the statements now:

(A) Some of the people who are allergic to penicillin are likely to be allergic to the new antibiotic.
This means that they will either stop taking the new medicine ahead of time or that it will not be effective for them. This actually weakens the argument.
(B) A course of treatment with the new antibiotic costs about the same as a course of treatment with either penicillin or erythromycin.
First of all, cost is out of scope. Even otherwise, people might have wanted to complete the course with new medicine if it was cheper, but since it is not there is no reason for them to. This neither strengthens nor weakens the argument.
(C) The new antibiotic has been shown to be effective in eradicating bacterial infections other than strep.
This is out of scope, but lets not rule it out for a moment.
(D) Some physicians have already begun to prescribe the new antibiotic instead of penicillin or erythromycin for the treatment of some strep infections.
Thank the physicians but they haven't done anything to strengthen our argument. They can prescribe the new medicine all they want but people may still not complete the dosage and get infected again. Silly people!!!
(E) Regardless of whether they take a traditional antibiotic or the new one, most patients feel fully recovered after taking the drug for three days.
This is our man. What it tells us is that, with old medicines, patients started feeling better in 3 days and hence stopped taking the dosage. With the new medicine too they would start feeling better only after 3 days; but by that time the new medicine would have done its job and hence no re-infection.


PS: Lets rule out C now

Traditionally, treatment is 7 day course of penicillin.
However, people stop after 3 days so reinfection is common.
A new antibiotic needs only 3 days (to work fully)

Conclusion: Re-infection will be less common in case of new antibiotic.

This should be true if people will take the new antibiotic for 3 days. Option (E) tells us that this is what happens. Most people feel fully recovered after 3 days whichever treatment they take. So it is likely that with the new treatment reinfection cases will be fewer.

A. Some of the people who are allergic to penicillin are likely to be allergic to the new antibiotic.

These cases are irrelevant to our argument since they can't get either treatment anyway.

B. A course of treatment with the new antibiotic costs about the same as a course of treatment with either penicillin or erythromycin.

The comparative cost of the two treatments is irrelevant. Patients who are prescribed a certain medicine will need to take that medicine since without prescription, they won't get anything else. So people who are prescribed a medicine is the same set as the people who take that medicine. Note that the same language is used in the second sentence as well "... reinfection is common in cases where those drugs are prescribed". Cases where it is prescribed = Cases where the patients take it.
Patients don't have a choice, whatever may be the cost, high or low.

C. The new antibiotic has been shown to be effective in eradicating bacterial infections other than strep.

Other infections are irrelevant.

D. Some physicians have already begun to prescribe the new antibiotic instead of penicillin or erythromycin for the treatment of some strep infections.

Irrelevant.

Answer (E)

E, since both drug will make patients feel fully recovered after 3 days, it's safe to assume they will stop taking them after 3 days.

The new antibiotic only needs 3 days to work. If people stop taking it after 3 days they shouldn't be reinfected.

They could be equally effective if used properly, but because more people stop after 3 days only the new antibiotic will be used properly and thus be more effective.

IMO: E

Main issue is: People seem to stop taking the antibotics after 3 days. So a drug has to be effective in 3 days.


A. Some of the people who are allergic to penicillin are likely to be allergic to the
new antibiotic.
>> Out of scope. Eliminate.

B. A course of treatment with the new antibiotic costs about the same as a course of
treatment with either penicillin or erythromycin.
>> Irrelevant. Does not explain why people stop taking antibiotics after 3 days. Eliminate. (Note that if you were using the 2 of 5 rule, this would be one of the 2 remaining options)

C. The new antibiotic has been shown to be effective in eradicating bacterial
infections other than strep.
>> Out of scope. Eliminate.

D. Some physicians have already begun to prescribe the new antibiotic instead of
penicillin or erythromycin for the treatment of some strep infections.
>> Irrelevant. Eliminate.

E. Regardless of whether they take a traditional antibiotic or the new one, most
patients feel fully recovered after taking the drug for three days.
>> Correct choice.

Ans choice E has a subtle nuance.

Patients feel fully recovered after 3 days with either drug. That is different from patients stopping taking the drug after 3 days. In essence E explains why they are stopping the drug after 3 days. They feel full recovered where as the course is 7 day. In the case of new drug, they not only feel fully recovered, but also the course is only 3 day.

Makes sense?

Great discussion here. Quick note:

As future MBA students, GMAT test takers tend to be too focused on costs. I can think of at least a few CR problems off the top of my head in which something related to "cost" is a trap answer. If you're going to choose an answer that relates to cost, I would really encourage you to spend a few extra seconds asking yourself whether the cost of the program or project really has anything to do with the argument itself.

Good one
The distinction in the question is about being CURED Vs. about FEELING BETTER
My answer is E

People "FEEL" better after three days hence they stop taking penicillin and Erythromycin (but they have not fully CURED. Remember peniillin and ertyomicin takes 7 days).

People when taking new antibiotic will again feel better after 3 days . The real difference is that they will actually be cured because new antibiotic works only in 3 days effectively curing the patient and also removing any chance of reinfection

First, let's break up this argument into premises and conclusions.

Premises:
traditional strep treatment takes 7 days
many people stop taking their medication after three days and become infected again
A new antibiotic only takes three days to work

Conclusion : the new 3-day treatment will reduce reinfection rates as compared with the 7-day treatments.

A. Some of the people who are allergic to penicillin are likely to be allergic to the new antibiotic. --- out of scope.

B. A course of treatment with the new antibiotic costs about the same as a course of treatment with either penicillin or erythromycin. --- oos

C. The new antibiotic has been shown to be effective in eradicating bacterial infections other than strep. --- even if infection other then strep, it will be new infection not reinfection. out

D. Some physicians have already begun to prescribe the new antibiotic instead of penicillin or erythromycin for the treatment of some strep infections. --- good but not helping in explanation

In order to understand why (E) is the correct answer, let's take a moment to understand this argument. The problem with the 7-day antibiotics is that people stop taking them after three days, which means that they aren't completely effective.

In order to prevent reinfection, the 3-day course of antibiotics must be effective without the same issues as the 7-day course of antibiotics. The passage doesn't tell us why people stop taking the pills after three days, so we rely on logic to determine

I always like to predict some answers before looking at the choices. Why would people stop taking the pills? Well, it could be because the start to feel better after a few days, or because the pills are expensive and they don't want to buy 7-days worth of pills, or because they don't understand the doctor's instructions.

We need to strengthen the argument that the 3-day course of pills will prevent reinfection.

Answer choice (E) says:
Regardless of whether they take a traditional antibiotic or the new one, most patients feel fully recovered after taking the drug for three days.


Let's think about this. If people feel fully recovered after just three days of taking the pill, then they are unlikely to continue to take the pill. This is one of the reasons that I predicted above. Once people feel better, they will stop taking the medicine.

So, if the patient takes the 7-day medication, feels better after three days, and stops taking the pills, then she will become re-infected. On the other hand, if the person takes the 3-day medication and starts feeling better after three days, then she will not be re-infected because the pills have already worked!

Since you feel better after three days with all of the pills, the 3-day pill will be more effective because it actually cures you in that time. That is why it supports the idea that the 3-day treatment will reduce re-infections.

A. People being allergic to drug is not the concern of the passage.
B. The cost of the course of treatment is also not the concern of the passage.
C. Only strep infection is been talked about here. So, other bacterial infections are out of scope.
D. This could be because of the efficiency or the price of new antibiotic. So, this doesn’t strengthen the argument.
E. This statement strengthens the argument as people feel fully recovered after taking the course for 3 days but it is mentioned in the argument that re-infection is common in traditional treatment of strep infection if the patients stops taking antibiotic any day before the whole course gets complete. So, people might stop taking traditional antibiotics after 3 days when they start feeling recovered and thus get exposed to re-infection. Hence, E is the answer.

GMATNinja VeritasKarishma

Can one of you experts jump in on this one please?
I chose B. Here's my thought process behind doing so:
The conclusion is : Reinfection will probably be less common in cases where the new antibiotic is prescribed than in cases where either penicillin or erythromycin is prescribed
To strengthen this I should look for an answer choice that rules out any possibility of patients NOT actually following what's been prescribed because of other constraints (Cost being one such constraint). That is, if the cost of the new treatment were prohibitively high, patients might not take the prescribed antibiotics and take the cheaper ones (penicillin or erythromycin) instead, in which case reinfection will probably NOT be less common.
Answer choice B seems to be along the lines of my pre-thinking.
Can you please point out any fundamental flaw in my reasoning?

Thanks
Debo

MartyTargetTestPrep GMATNinja i read this question multiple times but honestly felt that there is not a good answer. i initially chose (D) since it can be inferred that physicians support the new drug. but how can E be the right answer? can you please explain your thought process?

First, let's eliminate (D).

D. Some physicians have already begun to prescribe the new antibiotic instead of penicillin or erythromycin for the treatment of some strep infections.

What (D) says may seem to represent an endorsement of the new drug by physicians. At the same time, whether what (D) says means that the new drug works is somewhat debatable.

In any case, the truth is that physicians have been prescribing penicillin and erythromycin as well. So, even if (D) does represent some kind of endorsement of the drug by physicians, the fact that physicians are prescribing this new drug does not indicate in that it is different from or more effective than other drugs. After all, all of the drugs are being prescribed.

So, (D) does not strengthen the argument.

Now, let's consider (E).

E. Regardless of whether they take a traditional antibiotic or the new one, most patients feel fully recovered after taking the drug for three days.

OK, this choice is a bit tricky. Why? Because the passage says that many people stop taking penicillin or erythromycin after only three days. So, we already know that there is some reason why people stop taking penicillin or erythromycin after only three days. We just don't know what that reason is until we see (E). So, (E) seems to merely provide an explanation for the pattern of behavior described in the passage, and thus (E) may not seem to be a strengthener.

However, (E) does something else as well.

(E) tells us that people who take the new drug DO NOT FEEL BETTER SOONER THAN THREE DAYS AFTER THEY START TAKING IT.

Notice why that information strengthens the argument. That information indicates that people have a reason to stop taking penicillin or erythromycin early but won't have that same reason to stop taking the new drug early. After all, they feel good in three days, in other words, right when they are supposed to stop taking the new drug anyway.

So, (E) shows how the two drugs are different: people feel good before they are supposed to stop taking penicillin or erythromycin but feel good right when they are supposed to stop taking the new drug. Thus, (E) indicates why reinfection will probably be less common in cases where the new antibiotic is prescribed than in cases where either penicillin or erythromycin is prescribed.

What a tricky question.
_________________

A. Some of the people who are allergic to penicillin are likely to be allergic to the new antibiotic.
This weaken the argument of administrating the new antibiotic


B. A course of treatment with the new antibiotic costs about the same as a course of treatment with either penicillin or erythromycin.
Out of context cost was never considered


C. The new antibiotic has been shown to be effective in eradicating bacterial infections other than strep.
This too weak the main idea of administration is elemination strep


D. Some physicians have already begun to prescribe the new antibiotic instead of penicillin or erythromycin for the treatment of some strep infections.
This too is out of context doesn't quite help us understand why the new antibiotic is helpful


E. Regardless of whether they take a traditional antibiotic or the new one, most patients feel fully recovered after taking the drug for three days.
Yes definitely if they feel quite recovered then it's good idea and people will definitely intake the medicine hence IMO E

How are the patients' feelings relevant here? If the course of the new antibiotic is three day long, it must be enough to understand that the infection is cured. How does it matter whether the patients feel better in three days?

[quote="prasannar"]The traditional treatment of strep infections has been a seven-day course of antibiotics, either penicillin or erythromycin. However, since many patients stop taking those drugs within three days, reinfection is common in cases where those drugs are prescribed. A new antibiotic requires only a three-day course of treatment. Therefore, reinfection will probably be less common in cases where the new antibiotic is prescribed than in cases where either penicillin or erythromycin is prescribed.


Does the question say: In the existing treatment, Patients stop taking Penicillin before 3 days also or is it after 3 days do they stop taking the medication? Confusion due to the use of word within.

Understanding the argument -
The traditional treatment of strep infections has been a seven-day course of antibiotics, either penicillin or erythromycin. Fact
However, since many patients stop taking those drugs within three days, reinfection is common in cases where those drugs are prescribed. Fact. "However" states the contrast.
A new antibiotic requires only a three-day course of treatment. Fact
Therefore, reinfection will probably be less common in cases where the new antibiotic is prescribed than in cases where either penicillin or erythromycin is prescribed. - Conclusion.

The assumption is that the patients will use the new medication for three days as prescribed. Because if they do not take the new medication for three days, the conclusion will shatter. We need to find an option that confirms this assumption or minimum condition or a missing premise.

Option Elimination -

A. Some of the people who are allergic to penicillin are likely to be allergic to the new antibiotic. Some can be at least 2. So, two people allergic to penicillin will likely be allergic to the new antibiotic. So, if they are less likely to take the new drug as prescribed, then at best, it can be a very weak weakener.

B. A course of treatment with the new antibiotic costs about the same as a course of treatment with either penicillin or erythromycin. - The "cost" can apply in real scenarios if the prescribed drug is expensive and the insurance only approves the generic. But that could have been the case for earlier drugs as well, "penicillin or erythromycin." So, the conclusion construction rules out this scenario by saying that "the new antibiotic is prescribed than in cases where either penicillin or erythromycin is prescribed." We consider the scenario where it's prescribed (and taken); otherwise, there can be several scenarios. Wrong.

C. The new antibiotic has been shown to be effective in eradicating bacterial infections other than strep. - Other infections are out of scope.

D. Some physicians have already begun to prescribe the new antibiotic instead of penicillin or erythromycin for the treatment of some strep infections. - Some can be at least 2. Two physicians starting to prescribe by no means can lead to the conclusion that the reinfection will be less.

E. Regardless of whether they take a traditional antibiotic or the new one, most patients feel fully recovered after taking the drug for three days. - Oh, ok. This is why they stop taking penicillin or erythromycin in 3 days. Still, as the recommended dosage for the drug "penicillin or erythromycin" works in 7 days, most of them stop taking it after three days, as they are not yet cured, so re-infection is logical. But for the new drug, the recommended period is three days because three days is the time required to cure. So, they feel better when they stop it and are scientifically cured.