A certain drug, when taken by patients with high blood pressure, was

Question

A certain drug, when taken by patients with high blood pressure, was found to lower blood pressure to high-normal levels, or from an average of 30 percent to an average of 10 percent above normal. However, a survey of patients with normal blood pressure found that almost 80 percent exercised at least 5 days per week for 30 minutes and maintained a normal blood pressure. Therefore, the drug is not as effective in reducing blood pressure in patients with high blood pressure as is exercise.

The validity of the above conclusion depends on the truth of which of the following?

A. Frequent exercise has the same effect on blood pressure in all patients.

B. No patient with high blood pressure successfully achieved below-normal levels with the drug alone.

C. Patients with normal blood pressure maintained healthy diets for the duration of the study.

D. Few of the patients with high blood pressure exercise regularly.

E. The drug has little or no effect on patients with normal blood pressure.

Testluv · Accepted Answer

Hi,

the correct answer is definitely choice D. We can use the Kaplan denial test to prove it. The author concludes that the drug isn't as effective as exercise in treating high blood pressure. Choice D reads:

"FEW of the patients with high blood pressure exercise regularly"

whose denial is:

"MANY of the patients with high blood pressure exercise regularly"

in which case the argument falls apart (because even though they exercise their blood pressure didn't go down until they were on the drug.) So, when D is false, the argument can't stand. Thus, the argument depends on choice D.

As another poster pointed out, choice A is extreme for an assumption question. The author's reasoning does not depend on the idea that exercise has the same effect on blood pressure in ALL patients. For example, does he have to assume exercise will have a similar effect in LOW-blood pressure patients? Of course not. Thus, his reasoning does NOT depend on choice A.

Another poster pointed out that the argument uses flawed reasoning in that it illogically compares two different groups. Although that's true, that certainly doesn't mean that it is not a good question. In many arguments, the arguer's reasoning will be flawed.

KissGMAT · Answer

D . Concidering that sample set of people, who generally excercise, consists of some peole who have high blood presure.

amp0201 · Answer

Answer should be D. But can some one please explain the solution by logically negating the answer choice. I believe the logical negation of the answer choice D will be-

None  of the patients with high blood pressure exercise regularly. I am not sure if this statement is weakening the argument. Thank You.

Thanks,
Akhil M.Parekh

dwivedys · Answer

in order to conclusively prove that exercise is more effective than the drug in keep bp under check we must create two samples of people - one who exercise and dont take drug and the other who dont exercise but take the drug. Then we should compare their blood pressures. If "normal" people tend to maintain healthy bp with exercise and those who take drug are not able to bring their bp to normal levels - it shows that the drug has failed to be effective.

I chose D purely by elimination because the other choices were making no sense. In fact I believe its a poor quality question because we cannot logically compare healthy people who dont have bp to those who have --- those with BP may or may not respond to exercise in the same way as normal people do (for whom exercise alone may be sufficient to maintain healthy bp).

nusmavrik · Answer

OA is wrong. I fact i'm sure about it.
However A fixes the argument.
The argument doesn;t talk about the low blood pressure. Choice A means that regardless of the blood pressure, patients can benefit from the exercise.Hence drug is not as effective as the exercise.

D limits the scope of the argument making it untenable.

mc · Answer

A is too strong to be a correct GMAT answer, IMO.

nusmavrik · Answer

Hi Testluv
Thanks. How do you this is assumption question? Sorry I think I missed the type of Q. Can you please elaborate?

Here are a few examples of questions that signal an assumption question: 
Which of the following is an assumption on which this argument depends?
The explanation above assumes that......
Which of the following is an assumption made in drawing the conclusion above?
The conclusion drawn above is based on the assumption that

dwivedys · Answer

If the high bp people both use drugs and exercise frequently and lets say that by doing both they were able to keep their bp in check - to which of the two would we attribute this effect to? (to exercise or to drug?) it would still leave open the possibility that it was NOT the exercise but the drug that was keeping the bp normal and hence comparing this set of people with the set that exercises regularly and keeps bp in check would not yield a conclusive result.

Besides - what do we mean by saying Exercise is more effective in keeping bp under check? For normal people BP is not an issue to begin with so how can we say that exercise is helping them keep the bp in check? If they had BP to begin with and then they exercised and kept BP in check then we could conclude that exercise is perhaps more effective than the drug is in keeping the BP in check. I am not convinced its a good quality question but anyway... it's not a big deal.

Testluv · Answer

Hi,

great questions guys! Let's start with nusmavrik's:

Because the question stem asks for something that the conclusion's validity DEPENDS on. An idea on which a conclusion depends is a necessary assumption. Let me know if you seek further elaboration

Here are dwivedys' questions:

That would indeed be a conundrum. Fortunately, we don't have to deal with it. The author's evidence already established that this group of high-blood pressure-patients' reduced their blood pressure by taking the drug. Thus, their blood pressure was high UNTIL they took the drug.

Now, if we learn that (many of) the high-blood-pressure patients were also regular exercisers (as per the denial of choice D), then we know that this group of patients had high blood pressure  even though  they are regular exercisers. Basically, we'd have a group of people who exercised regularly and who had high blood pressure who  then  alleviated their high blood pressure by taking the drug. That seriously damages the author's argument that the drug is not as effective as regular exercise.

As always, we have to attach a commonsense interpretation given the context of the argument. Look at the first sentence: "a certain drug...was found to lower blood pressure". Thus, the only thing the author could possibly intend to mean when he claims that the drug is "not as effective" as exercise is that exercise is better at lowering blood pressure.

I don't see any design flaws with this question!

dwivedys · Answer

Thanks...

Your explanation does make sense. It just didn't occur to me that way when I read the question first.

CrackverbalGMAT · Answer

Hey Akhil, 
The problem here is more language than anything else. 
"Few of the patients with high blood pressure exercise regularly" would mean that NO ONE exercised. 
(A few, on the other hand, means that there were a couple or more individuals that did exercise. )
Therefore on negation the statement would read "ALL/ MOST of the patients with high BP exercise regularly"

Hope that helps, 
Ajeeth Peo

kinjiGC · Answer

A certain drug, when taken by patients with high blood pressure, was found to lower blood pressure to high-normal levels, or from an average of 30 percent to an average of 10 percent above normal. However, a survey of patients with normal blood pressure found that almost 80 percent exercised at least 5 days per week for 30 minutes and maintained a normal blood pressure. Therefore, the drug is not as effective in reducing blood pressure in patients with high blood pressure as is exercise. 
The validity of the above conclusion depends on the truth of which of the following?

Premise 1 : Drug decreased from 30% to 10% above normal.
Premise 2 : 80% exercised frequently and could  maintain  normal blood pressure.
Conclusion : Exercising is more effective than drug

A. Frequent exercise has the same effect on blood pressure in all patients.
Same effect -> high blood pressure patients can maintain the blood pressure. I presume high remains high - It doesn't make sense and refutes the author's argument.
 
B. No patient with high blood pressure successfully achieved below-normal levels with the drug alone. 
Part of the premise : The patients decreased 30% to 10% - Cannot be the assumption.

C. Patients with normal blood pressure maintained healthy diets for the duration of the study. 
- Out of scope

D. Few of the patients with high blood pressure exercise regularly. 
- Negation : Most of the patients with high blood pressure exercise regularly - Breaks the conclusion

E. The drug has little or no effect on patients with normal blood pressure.
- Out of scope.

Hence D)

Chandni170 · Answer

Hi,

I just gave a test and came across this question. However, the answer choices are slightly different. Here's the question:

A certain drug, when taken by patients with high blood pressures, was found to lower the blood pressure to high-normal levels, or from an average of 30 percent to an average of 10 percent above normal. However a survey of patients with normal blood pressures found that almost 80 percent exercised atleast 5 days per week for 30 minutes and maintained a normal blood pressure. 
Therefore, the drug is not as affective in reducing blood pressure in patients with high blood pressure as is exercise. The validity of the above conclusion depends on the truth of which of the following ?

A. None of the patients with high blood pressure exercise regularly. 
B. No patient with high blood pressure successfully achieved below-normal levels with drug alone. 
C. Patients with normal blood-pressure maintained healthy diets for the duration of the study.
 D. Daily exercise has the same effect on the blood pressures in all patients.  
E. The drug has little or no effects on patients with normal blood pressures.

The OA for this is D. However, the original post does not support this OA.

During the test, I had narrowed down to A and D, and I've read some convincing explanations for both, however, I'm still confused between A and D.

Experts- Kindly help me eliminate A and justify D.

Thanks & Regards,
Chandni

kinjiGC · Answer

I am going to discuss only the two options A and D.

Premise 1: Drugs can reduce blood pressure to some extent and not completely.
Premise 2 : 80% of the patients with normal blood pressure can maintain their blood pressure if they exercise.
Conclusion : Exercise is better than Drugs.

A big leap of faith. Drugs doesn't work on high blood pressure and using exercise the patients with normal blood pressure can maintain their blood pressure.

A. None of the patients with high blood pressure exercise regularly.
This statement isolates the effect to only the drugs and not the to exercise. Still we cannot compare the effects and come to a conclusion.

D. Daily exercise has the same effect on the blood pressures in all patients.
Now, this connects the dots. Daily exercise has the same effects on all patients - Including high blood pressure patients.
So high blood pressure patients can have normal blood pressure if they exercise regularly.

jitinarora · Answer

Hi,

Conclusion: Drug is not as effective as exercise is in reducing blood pressure in patients with high blood pressure.

Premise 1: Certain drug can lower BP in patients with high BP to high-normal levels (from an avg 30% above normal to 10% above normal)
Premise 2: Survey of patients with normal BP found that almost 80% exercised at least 5 days per week for 30 minutes and maintained a normal BP.

Now, based on these premises the author has concluded that drug is not as effective as exercise is in reducing BP in patients.

Lets use the falsification method.

Q. Under what conditions drug will be as effective as exercise is in reducing the blood pressure in patients?

1. The patients that maintained normal blood pressure could do so by exercising as well as taking the drug as with only exercising they are able to maintain their blood pressure levels above 10% of normal.

Assumption (Negate the above statement):

Patients with normal blood pressure levels are able to maintain normal BP only with exercise.

or, we can say that

Patients that take drugs, few if any (means almost none of them) exercise regularly.

Therefore, option D is the correct answer.

- Thanks

VerbalBot · Answer

Automated notice from GMAT Club VerbalBot: 

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

 This post was generated automatically.

A certain drug, when taken by patients with high blood pressure, was

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Critical Reasoning (CR) Questions

A certain drug, when taken by patients with high blood pressure, was

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards