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# Epidemiologist: In Brazil, schistosomiasis and malaria are

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Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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03 May 2013, 01:43
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31% (01:47) correct 69% (01:37) wrong based on 2097 sessions

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Epidemiologist: In Brazil, schistosomiasis and malaria are the two most common infectious diseases. Over the past five years, schistosomiasis has been primarily responsible for the overall increase in infectious disease cases. Therefore it is likely that there were more cases of schistosomiasis than malaria five years ago.

Which of the following most strengthens the argument above?

A. Over the past five years, the percentage of infectious disease cases caused by schistosomiasis has remained unchanged, but the percentage of cases caused by malaria has increased substantially.

B. Trends in infectious disease data tend to persist for decades, unless there is a major breakthrough in treatment regimens.

C. Five years ago, many more people died from schistosomiasis than died from malaria.

D. Over the past five years, the percentage of infectious disease cases caused by malaria was not significantly greater than the percentage of cases caused by schistosomiasis.

E. Over the past five years, the percentage of infectious disease cases caused by diseases other than malaria and schistosomiasis did not increase substantially.
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Re: Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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04 Mar 2014, 23:44
13
8
thelosthippie wrote:
Epidemiologist: In Brazil, schistosomiasis and malaria are the two most common infectious diseases. Over the past five years, schistosomiasis has been primarily responsible for the overall increase in infectious disease cases. Therefore it is likely that there were more cases of schistosomiasis than malaria five years ago.

Which of the following most strengthens the argument above?

A. Over the past five years, the percentage of infectious disease cases caused by schistosomiasis has remained unchanged, but the percentage of cases caused by malaria has increased substantially.

B. Trends in infectious disease data tend to persist for decades, unless there is a major breakthrough in treatment regimens.

C. Five years ago, many more people died from schistosomiasis than died from malaria.

D. Over the past five years, the percentage of infectious disease cases caused by malaria was not significantly greater than the percentage of cases caused by schistosomiasis.

E. Over the past five years, the percentage of infectious disease cases caused by diseases other than malaria and schistosomiasis did not increase substantially.

Yes, the argument is analytical. Let's understand it first.

Two most common infectious diseases: schistosomiasis and malaria
Infectious disease cases have increased in the past 5 yrs (say from a total of 100 five yrs ago to 150 now). Schistosomiasis led to this increase so probably many of the extra 50 cases are those of Schistosomiasis.
Conclusion: It is likely that there were more cases of schistosomiasis than malaria five years ago i.e. say 5 yrs ago, there were 70 schistosomiasis cases while there were 20 malaria cases (and 10 other disease cases)

We need to strengthen the conclusion.

A. Over the past five years, the percentage of infectious disease cases caused by schistosomiasis has remained unchanged, but the percentage of cases caused by malaria has increased substantially.
If most of the increase in cases is due to schistosomiasis but the % of schistosomiasis in the total cases is the same, it means, most of the cases comprised of schistosomiasis earlier too. So this strengthens our conclusion. Let's take a look using numbers too.

Today if still 70% infectious disease cases are those of schistosomiasis, it means there are 105 schistosomiasis cases today (an increase of 35 out of the extra 50).
If malaria cases have increased to 30%, number of malaria cases would be 45 i.e. an increase of 15 out of the extra 50.
We see that schistosomiasis cases account for most of the extra 50 cases i.e. they account for 35 cases. So this strengthens our conclusion.

B. Trends in infectious disease data tend to persist for decades, unless there is a major breakthrough in treatment regimens.
We don't know if there has been a major breakthrough in treatment regimens on any disease in the past 5 yrs. It is possible that 5 yrs ago there were more cases of malaria than schistosomiasis but breakthrough in treatment regimen of malaria led to a decline in its cases.

C. Five years ago, many more people died from schistosomiasis than died from malaria.
Number of deaths is irrelevant to the number of cases since the argument doesn't say which disease is more serious, has better medicines etc. It is possible that schistosomiasis had fewer cases 5 yrs ago but is much more serious and led to death more often.

D. Over the past five years, the percentage of infectious disease cases caused by malaria was not significantly greater than the percentage of cases caused by schistosomiasis.
This says that % of malaria cases was not much greater (though perhaps a little greater) than % of schistosomiasis cases over the past 5 years. If anything, this weakens our conclusion. It indirectly implies that out of 100 cases 5 yrs ago, malaria cases were slightly more than schistosomiasis cases.

E. Over the past five years, the percentage of infectious disease cases caused by diseases other than malaria and schistosomiasis did not increase substantially.
This says that % of other diseases has held steady. So if earlier, 10% of cases (10 cases) were other diseases, still 10% of cases (i.e. 15 cases) are other diseases. This doesn't say whether 5 yrs ago there were more cases of schistosomiasis or malaria.

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Re: Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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03 May 2013, 03:17
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Fact1: In Brazil, schistosomiasis and malaria are the two most common infectious diseases.

Fact2: Over the past five years, schistosomiasis has been primarily responsible for the overall increase in infectious disease cases.

Conclusion: it is likely that there were more cases of schistosomiasis than malaria five years ago.

choice A is the correct answer because:

fact2 says that schistosomiasis has been primarily responsible for the overall increase in infectious disease cases over past 5 years.

Now if its percentage has remained unchanged as said in choice A then that means that it was already having more cases as even with same percentage it is still primarily responsible for the overall increase in infectious disease cases as compared to malaria whose percentage has increased.
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Re: Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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04 May 2013, 03:29
1
thelosthippie wrote:
Epidemiologist: In Brazil, schistosomiasis and malaria are the two most common infectious diseases. Over the past five years, schistosomiasis has been primarily responsible for the overall increase in infectious disease cases. Therefore it is likely that there were more cases of schistosomiasis than malaria five years ago.

Which of the following most strengthens the argument above?

A. Over the past five years, the percentage of infectious disease cases caused by schistosomiasis has remained unchanged, but the percentage of cases caused by malaria has increased substantially.

B. Trends in infectious disease data tend to persist for decades, unless there is a major breakthrough in treatment regimens.

C. Five years ago, many more people died from schistosomiasis than died from malaria.

D. Over the past five years, the percentage of infectious disease cases caused by malaria was not significantly greater than the percentage of cases caused by schistosomiasis.

E. Over the past five years, the percentage of infectious disease cases caused by diseases other than malaria and schistosomiasis did not increase substantially.

Can someone quite eloborate on answer choices , i'm not quite getting this. please.

I feel C is the correct answer .

Question analysis:

schistosomiasis ->major cause in overall increase in infectious disease cases

conclusion: there were more cases of schistosomiasis thanb of malaria five years ago.

So we know that the percentage growth of schistosomiasis is greater to the percentage increase of malaria over the five years .

If only we can prove malaria and schistosomiasis were of same levels before five years or schistosomiasis was of much higher level than the cases of malaria we wold have achieved our goal.

Only option C satisfies this.
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Re: Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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04 May 2013, 21:17
5
Hi,

Question analysis:

schistosomiasis ->major cause in overall increase in infectious disease cases :You are correct here

conclusion: there were more cases of schistosomiasis thanb of malaria five years ago.

So we know that the percentage growth of schistosomiasis is greater to the percentage increase of malaria over the five years :Wrong we cant assume this.
May be the base of malaria was so small that a greater percentage will not mean more cases.Ex lets assume 10 cases of malaria and 90 of schistosomiasis means even if malaria grows my 100% to 20 and schistosomiasis doesnt grow,still schistosomiasis will contribute more cases.

If only we can prove malaria and schistosomiasis were of same levels before five years or schistosomiasis was of much higher level than the cases of malaria we wold have achieved our goal.
You are right here and this is proved by option A..
The reasoning is that as per option A ,the percentage of infectious disease cases caused by schistosomiasis has remained unchanged, but the percentage of cases caused by malaria has increased substantially and yet schistosomiasis has been primarily responsible for the overall increase in infectious disease cases..This means that schistosomiasis was of much higher level than the cases of malaria9as you have said above).

Only option C satisfies this. Wrong as option C talks only about death and not about number of cases so easy to eliminiate this option.

In these kind of question try to eliminate as many option as poosible so that your foucus is on understanding the implication of the options remaining.
Hope this helps.
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Re: Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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04 May 2013, 21:37
1
ssbisht wrote:
Hi,

Question analysis:

schistosomiasis ->major cause in overall increase in infectious disease cases :You are correct here

conclusion: there were more cases of schistosomiasis thanb of malaria five years ago.

So we know that the percentage growth of schistosomiasis is greater to the percentage increase of malaria over the five years :Wrong we cant assume this.
May be the base of malaria was so small that a greater percentage will not mean more cases.Ex lets assume 10 cases of malaria and 90 of schistosomiasis means even if malaria grows my 100% to 20 and schistosomiasis doesnt grow,still schistosomiasis will contribute more cases.

If only we can prove malaria and schistosomiasis were of same levels before five years or schistosomiasis was of much higher level than the cases of malaria we wold have achieved our goal.
You are right here and this is proved by option A..
The reasoning is that as per option A ,the percentage of infectious disease cases caused by schistosomiasis has remained unchanged, but the percentage of cases caused by malaria has increased substantially and yet schistosomiasis has been primarily responsible for the overall increase in infectious disease cases..This means that schistosomiasis was of much higher level than the cases of malaria9as you have said above).

Only option C satisfies this. Wrong as option C talks only about death and not about number of cases so easy to eliminiate this option.

In these kind of question try to eliminate as many option as poosible so that your foucus is on understanding the implication of the options remaining.
Hope this helps.

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Re: Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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10 May 2013, 03:58
(P)->Schi caused overall inc in no. of cases in infection disease in last five years
(P)->Schi and malaria 2 most common diseases
(C)-> Higher no. of schi cases than malaria cases

(E)->out of scope
(D)->restates the conclusion
(C)-> out of scope, talks abt data 5 years ago
(B)-> No breakthru in treatment coudn't explain increase in schi cases than malaria
(A)-> Bingo. Take the no. of schi cases as 100 and malaria as 30 5yrs ago. Now as per ans choice %age of schi cases has remained unchanged which means schi cases 100 and malaria cases has 50% increment, which come to 60. Proves that there are more no. of schi cases than malaria cases after 5 years

However, I was thinking if the reason for answering is correct or not. Also, what cud have been the assumption in this case?
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Re: Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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10 May 2013, 04:23
1
kawan84 wrote:
(P)->Schi caused overall inc in no. of cases in infection disease in last five years
(P)->Schi and malaria 2 most common diseases
(C)-> Higher no. of schi cases than malaria cases

(E)->out of scope
(D)->restates the conclusion
(C)-> out of scope, talks abt data 5 years ago
(B)-> No breakthru in treatment coudn't explain increase in schi cases than malaria
(A)-> Bingo. Take the no. of schi cases as 100 and malaria as 30 5yrs ago. Now as per ans choice %age of schi cases has remained unchanged which means schi cases 100 and malaria cases has 50% increment, which come to 60. Proves that there are more no. of schi cases than malaria cases after 5 years

However, I was thinking if the reason for answering is correct or not. Also, what cud have been the assumption in this case?

You are going in right direction but getting confused with numbers.No offense but had it been a quant question you could have got it wrong.
Example a 50% increase in malaria in your case will take the count to 45 from 30 as 50% of 30 is 15.
Similarly the count of schi cases will go up in the same proportion to keep it %tage constant,which is around 77% ( 100/100+30)

You can look at my posts above to get an understanding of how to approach such question without getting into numbers.
Hope it helps.

thanks
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Re: Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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10 May 2013, 09:33
Thanks for correction ssbisht. Small mistakes, big fine.. completely agree with your thoughts. I've been thru ur posts, however, my question still remains regarding the calc of schi cases when the % was unchanged
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Re: Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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18 Feb 2014, 21:52
this one is totally about math... higher growth ,but the number after 5 yrs is still smaller ,so the original number must be smaller also
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Re: Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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03 Mar 2014, 08:14
1
1
A seems the best for the following reasoning, though I went with A, D seems very close, any alternate explanation why D can be eliminated?

A. Over the past five years, the percentage of infectious disease cases caused by schistosomiasis has remained unchanged, but the percentage of cases caused by malaria has increased substantially.
From the argument, we gather that Schist has been primarily responsible for overall iincrease in ifectious diseases. Now lets come to this answer. Schist percentage remains same. With this infor schist is still major contributor, so let us safely assume that schist makes up 60% of infectious diseases. If malaria made significant increases, then malaria may have gone from 15% five years ago to 40% now, still a substantial increase. Therefore this answer gives us good reason to believe schist had more cases than malaria five years ago Correct answer.
B. Trends in infectious disease data tend to persist for decades, unless there is a major breakthrough in treatment regimens.
The words like tend to imply a good possibility, but this in itself is not sufficient to best support above argument.
C. Five years ago, many more people died from schistosomiasis than died from malaria.
This choice is misleading, more deaths does not mean more cases of infection.
D. Over the past five years, the percentage of infectious disease cases caused by malaria was not significantly greater than the percentage of cases caused by schistosomiasis.
This only talks about past 5 years, this choice does not rule out possibility of more cases of malaria 5 years ago
E. Over the past five years, the percentage of infectious disease cases caused by diseases other than malaria and schistosomiasis did not increase substantially.
Other diseases not increasing does not give us enough information to make a comparison between Malaria and schist.
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Re: Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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23 Sep 2014, 06:48
From the argument, we gather that Schist has been primarily responsible for overall increase in infectious diseases.

Schist percentage remains same. With this information schist is still major contributor, so let us safely assume that schist makes up 60% of infectious diseases. If malaria made significant increases, then malaria may have gone from 15% five years ago to 40% now, still a substantial increase. Therefore this answer gives us good reason to believe schist had more cases than malaria five years ago

So choice A is correct.
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Re: Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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23 Sep 2014, 21:07
Asians love this type of questions ))))) simple math

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Re: Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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16 Jun 2015, 02:46
Can someone explain the logic of the whole argument???

I am unable to follow...
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Re: Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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06 May 2017, 20:18
Here are the mathematical proof that answer 1 is correct.

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Re: Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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06 May 2017, 23:18
VeritasPrepKarishma wrote:
thelosthippie wrote:
Epidemiologist: In Brazil, schistosomiasis and malaria are the two most common infectious diseases. Over the past five years, schistosomiasis has been primarily responsible for the overall increase in infectious disease cases. Therefore it is likely that there were more cases of schistosomiasis than malaria five years ago.

Which of the following most strengthens the argument above?

A. Over the past five years, the percentage of infectious disease cases caused by schistosomiasis has remained unchanged, but the percentage of cases caused by malaria has increased substantially.

B. Trends in infectious disease data tend to persist for decades, unless there is a major breakthrough in treatment regimens.

C. Five years ago, many more people died from schistosomiasis than died from malaria.

D. Over the past five years, the percentage of infectious disease cases caused by malaria was not significantly greater than the percentage of cases caused by schistosomiasis.

E. Over the past five years, the percentage of infectious disease cases caused by diseases other than malaria and schistosomiasis did not increase substantially.

Yes, the argument is analytical. Let's understand it first.

Two most common infectious diseases: schistosomiasis and malaria
Infectious disease cases have increased in the past 5 yrs (say from a total of 100 five yrs ago to 150 now). Schistosomiasis led to this increase so probably many of the extra 50 cases are those of Schistosomiasis.
Conclusion: It is likely that there were more cases of schistosomiasis than malaria five years ago i.e. say 5 yrs ago, there were 70 schistosomiasis cases while there were 20 malaria cases (and 10 other disease cases)

We need to strengthen the conclusion.

A. Over the past five years, the percentage of infectious disease cases caused by schistosomiasis has remained unchanged, but the percentage of cases caused by malaria has increased substantially.
If most of the increase in cases is due to schistosomiasis but the % of schistosomiasis in the total cases is the same, it means, most of the cases comprised of schistosomiasis earlier too. So this strengthens our conclusion. Let's take a look using numbers too.

Today if still 70% infectious disease cases are those of schistosomiasis, it means there are 105 schistosomiasis cases today (an increase of 35 out of the extra 50).
If malaria cases have increased to 30%, number of malaria cases would be 45 i.e. an increase of 15 out of the extra 50.
We see that schistosomiasis cases account for most of the extra 50 cases i.e. they account for 35 cases. So this strengthens our conclusion.

B. Trends in infectious disease data tend to persist for decades, unless there is a major breakthrough in treatment regimens.
We don't know if there has been a major breakthrough in treatment regimens on any disease in the past 5 yrs. It is possible that 5 yrs ago there were more cases of malaria than schistosomiasis but breakthrough in treatment regimen of malaria led to a decline in its cases.

C. Five years ago, many more people died from schistosomiasis than died from malaria.
Number of deaths is irrelevant to the number of cases since the argument doesn't say which disease is more serious, has better medicines etc. It is possible that schistosomiasis had fewer cases 5 yrs ago but is much more serious and led to death more often.

D. Over the past five years, the percentage of infectious disease cases caused by malaria was not significantly greater than the percentage of cases caused by schistosomiasis.
This says that % of malaria cases was not much greater (though perhaps a little greater) than % of schistosomiasis cases over the past 5 years. If anything, this weakens our conclusion. It indirectly implies that out of 100 cases 5 yrs ago, malaria cases were slightly more than schistosomiasis cases.

E. Over the past five years, the percentage of infectious disease cases caused by diseases other than malaria and schistosomiasis did not increase substantially.
This says that % of other diseases has held steady. So if earlier, 10% of cases (10 cases) were other diseases, still 10% of cases (i.e. 15 cases) are other diseases. This doesn't say whether 5 yrs ago there were more cases of schistosomiasis or malaria.

Would you please explain the blue colored line a little bit. I can not relate this.
Option A could also be true if in 5 yrs ago, there were 20 schistosomiasis cases while there were 70 malaria cases (and 10 other disease cases). Am I correct?
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Re: Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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07 May 2017, 03:02
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I got stuck between A and D and went with D. What a disaster.
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Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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11 Dec 2017, 02:33
VeritasPrepKarishma wrote:
thelosthippie wrote:
Epidemiologist: In Brazil, schistosomiasis and malaria are the two most common infectious diseases. Over the past five years, schistosomiasis has been primarily responsible for the overall increase in infectious disease cases. Therefore it is likely that there were more cases of schistosomiasis than malaria five years ago.

Which of the following most strengthens the argument above?

A. Over the past five years, the percentage of infectious disease cases caused by schistosomiasis has remained unchanged, but the percentage of cases caused by malaria has increased substantially.

B. Trends in infectious disease data tend to persist for decades, unless there is a major breakthrough in treatment regimens.

C. Five years ago, many more people died from schistosomiasis than died from malaria.

D. Over the past five years, the percentage of infectious disease cases caused by malaria was not significantly greater than the percentage of cases caused by schistosomiasis.

E. Over the past five years, the percentage of infectious disease cases caused by diseases other than malaria and schistosomiasis did not increase substantially.

Yes, the argument is analytical. Let's understand it first.

T
Quote:
wo most common infectious diseases: schistosomiasis and malaria
Infectious disease cases have increased in the past 5 yrs (say from a total of 100 five yrs ago to 150 now). Schistosomiasis led to this increase so probably many of the extra 50 cases are those of Schistosomiasis.
Conclusion: It is likely that there were more cases of schistosomiasis than malaria five years ago i.e. say 5 yrs ago, there were 70 schistosomiasis cases while there were 20 malaria cases (and 10 other disease cases)

We need to strengthen the conclusion.

A. Over the past five years, the percentage of infectious disease cases caused by schistosomiasis has remained unchanged, but the percentage of cases caused by malaria has increased substantially.
If most of the increase in cases is due to schistosomiasis but the % of schistosomiasis in the total cases is the same, it means, most of the cases comprised of schistosomiasis earlier too. So this strengthens our conclusion. Let's take a look using numbers too.

Today if still 70% infectious disease cases are those of schistosomiasis, it means there are 105 schistosomiasis cases today (an increase of 35 out of the extra 50).
If malaria cases have increased to 30%, number of malaria cases would be 45 i.e. an increase of 15 out of the extra 50.
We see that schistosomiasis cases account for most of the extra 50 cases i.e. they account for 35 cases. So this strengthens our conclusion.

B. Trends in infectious disease data tend to persist for decades, unless there is a major breakthrough in treatment regimens.
We don't know if there has been a major breakthrough in treatment regimens on any disease in the past 5 yrs. It is possible that 5 yrs ago there were more cases of malaria than schistosomiasis but breakthrough in treatment regimen of malaria led to a decline in its cases.

C. Five years ago, many more people died from schistosomiasis than died from malaria.
Number of deaths is irrelevant to the number of cases since the argument doesn't say which disease is more serious, has better medicines etc. It is possible that schistosomiasis had fewer cases 5 yrs ago but is much more serious and led to death more often.

D. Over the past five years, the percentage of infectious disease cases caused by malaria was not significantly greater than the percentage of cases caused by schistosomiasis.
This says that % of malaria cases was not much greater (though perhaps a little greater) than % of schistosomiasis cases over the past 5 years. If anything, this weakens our conclusion. It indirectly implies that out of 100 cases 5 yrs ago, malaria cases were slightly more than schistosomiasis cases.

E. Over the past five years, the percentage of infectious disease cases caused by diseases other than malaria and schistosomiasis did not increase substantially.
This says that % of other diseases has held steady. So if earlier, 10% of cases (10 cases) were other diseases, still 10% of cases (i.e. 15 cases) are other diseases. This doesn't say whether 5 yrs ago there were more cases of schistosomiasis or malaria.

Quote:
wo most common infectious diseases: schistosomiasis and malaria
Infectious disease cases have increased in the past 5 yrs (say from a total of 100 five yrs ago to 150 now). Schistosomiasis led to this increase so probably many of the extra 50 cases are those of Schistosomiasis.
Conclusion: It is likely that there were more cases of schistosomiasis than malaria five years ago i.e. say 5 yrs ago, there were 70 schistosomiasis cases while there were 20 malaria cases (and 10 other disease cases)

We need to strengthen the conclusion.

A. Over the past five years, the percentage of infectious disease cases caused by schistosomiasis has remained unchanged, but the percentage of cases caused by malaria has increased substantially.
If most of the increase in cases is due to schistosomiasis but the % of schistosomiasis in the total cases is the same, it means, most of the cases comprised of schistosomiasis earlier too. So this strengthens our conclusion. Let's take a look using numbers too.

Today if still 70% infectious disease cases are those of schistosomiasis, it means there are 105 schistosomiasis cases today (an increase of 35 out of the extra 50).
If malaria cases have increased to 30%, number of malaria cases would be 45 i.e. an increase of 15 out of the extra 50.
We see that schistosomiasis cases account for most of the extra 50 cases i.e. they account for 35 cases. So this strengthens our conclusion.]

VeritasPrepKarishma

Hi Karishma,

I am sorry but i am not able to get the solution.
The figures say this
Schitosomiasis=S , MALARIA=M , OTHERS=0
Earlier
total=100
S= 70% of 100= 70
Malaria = 20% OF 100= 20
Others= 10

in between an increase in cases of 50

Now,
Total= 150
S= UNCHANGED 70% OF 150= 105
(an increase of 35 out of the extra 50)
Malaria has increased to 30 percent = 30% OF 150= 45
It means others =5

Now according to this explanation the number of others has decreased corresponding to numbers that have increased because of Malaria. Seems right till here
But , no where in the option A it has been mentioned that the precentage of others has been increased or decreased .
If the second case malaria increased by 22 percent then total malaria cases will be 33 in 150 (( an increase in malaria cases
and total others cases will be 17
(( 11.33 percent and that also shows an increase in others cases))
So how does Option A strenghthens the whole argument .

First part of opton A is clear that the percentage of S CASES have been same then and now, and that shows that S is the market leader in infectious diseases then and now. But how does the second part that malaria percentage cases have increased help in strengthening the conclusion?
I am just trying to say that the second part of the option is really confusing. If i consider extreme cases then others and malaria cases increases will be nearly equal. And , to be more extreme it can be that S cases were and are 51 percent despite the numbers increase but Malarial cases were 25 earlier and now they are 49 percent. And clearly this option then becomes a mild weakener.
I just want to ask that can't the second part of the option be omitted ?
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Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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Updated on: 14 Jan 2018, 00:58
Like a math question, ones probably use logical sense and feeling to solve.
First, the conclusion talks about "cases" but option choices are all about percentages.
Next, noting that in A schistosomiasis helps the overall increase, but the percentage is unchanged (this is a pattern that appears in another gmat question) => there are too many cases of schistosomiasis. Meanwhile, malaria rapidly increases percentage but malaria does not help much to increase the overall => cases of malaria are not too many.

In D, "over past 5 years" = now

Originally posted by chesstitans on 24 Dec 2017, 20:24.
Last edited by chesstitans on 14 Jan 2018, 00:58, edited 1 time in total.
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Re: Epidemiologist: In Brazil, schistosomiasis and malaria are  [#permalink]

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14 Jan 2018, 00:20
mikemcgarry GMATNinja VeritasPrepKarishma

Can you please shed more light on D?

Karishma you gave the following explanation :

D. Over the past five years, the percentage of infectious disease cases caused by malaria was not significantly greater than the percentage of cases caused by schistosomiasis.
This says that % of malaria cases was not much greater (though perhaps a little greater) than % of schistosomiasis cases over the past 5 years. If anything, this weakens our conclusion. It indirectly implies that out of 100 cases 5 yrs ago, malaria cases were slightly more than schistosomiasis cases.

Can you please tell me if my understanding of this is correct?
Say there were 100 cases 5 years ago!
51%-M - 51 cases
49%-S- 49 cases

so S cases were less than M but since now S is the cause of most cases, S would have increased over time.

But we can't say S was greater 5 years ago?

Am i right?
Re: Epidemiologist: In Brazil, schistosomiasis and malaria are &nbs [#permalink] 14 Jan 2018, 00:20

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