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Blood banks will shortly start to screen all donors for NANB hepatitis
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Author:  eybrj2 [ 27 Jan 2012, 21:11 ]
Post subject:  Blood banks will shortly start to screen all donors for NANB hepatitis

Blood banks will shortly start to screen all donors for NANB hepatitis. Although the new screening tests are estimated to disqualify up to 5 percent of all prospective blood donors, they will still miss two-thirds of donors carrying NANB hepatitis. Therefore, about 10 percent of actual donors will still supply NANB-contaminated blood.

Which of the following inferences about the consequences of instituting the new tests is best supported by the passage above?


A) The incidence of new cases of NANB hepatitis is likely to go up by 10 percent.

B) Donations made by patients specifically for their own use are likely to become less frequent.

C) The demand for blood from blood banks is likely to fluctuate more strongly.

D) The blood supplies available from blood banks are likely to go down.

E) The number of prospective first-time donors is likely to go up by 5 percent.

Author:  KarishmaB [ 18 Aug 2015, 22:31 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

eybrj2 wrote:
Blood banks will shortly start to screen all donors for NANB hepatitis. Although the new screening tests are estimated to disqualify up to 5 percent of all prospective blood donors, they will still miss two-thirds of donors carrying NANB hepatitis. Therefore, about 10 percent of actual donors will still supply NANB-contaminated blood.

Q) which of the follwoing inferences about the consequences of instituting the new tests is best supported by the passage above?

a) The incidence of new cases of NANB hepatitis is likely to go up by 10 percent.

b) Donations made by patients specifically for their own use are likely to become less frequent.

c) The demand for blood from blood banks is likely to fluctuate more strongly.

d) The blood supplies available from blood banks are likely to go down.

e) The number of prospective first-time donors is likely to go up by 5 percent.


Quote:
At first I picked A thinking, suppose 10 people comprise 2/3rd of the people who carry NABH and donate blood ---> They donate to 10 people at least ---> those people get NABH as well (now NABH must be infectious otherwise why are Blood banks testing to find whether ppl have NABH or not)
So increase of 10 people --> ~ 10% increase in NABH infected people.

After knowing I picked the wrong answer, my fallacy is probably this:
We don't know the total number of NABH infected cases: it may be 20 or it may be 10 ---> supposing it is 20, then 10 people addition is ---> 2% increase not 10% OR if it is 100 cases of infections ---> then it is 10% ----> % increase may be 2-10% or more ---> this makes the option A to be MAY BE TRUE.

A conclusion MUST BE TRUE ---> D) says the blood supplies will decrease ---> YES because people are disqualified, so less blood is available from all the possible donors.

Please do let me know if I am right. And also, How i may improve in ASSUMPTION CR, I also take around 3:30 mins in medium-tough questions.


The problem with (A) is that the argument does not give us enough information to deduce that.

10% of actual donors will supply NANB contaminated blood. But does that mean that all this blood will be used? What if actually only 50% of the blood from a blood bank is used. Then the actual incidence of disease may increase by only 5% (assuming homogenous distribution).
Also, what if NANB infected people are the ones who need blood most often from blood banks. In that case, we may find very few new cases.
Hence, increase in the incidence of disease is a big jump.

(D) is straight forward. 5% fewer people will be able to donate blood due to new tests and that means reduced supply is an effect of the new test.
In inference questions, simpler is usually better.

For discussions on assumption questions, check my blog:
https://www.gmatclub.com/forum/veritas-prep-resource-links-no-longer-available-399979.html/?s=assu ... er&x=0&y=0

Author:  aragonn [ 21 Apr 2018, 08:16 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

Straight D, new screening tests are estimated to disqualify up to 5 percent of all prospective blood donors. means less people will donate. less supply of blood.

Author:  teaserbae [ 09 Apr 2019, 00:26 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

AjiteshArun ChiranjeevSingh VeritasKarishma aragonn
As per the question
Let's assume there are 100 people who donate blood
now 15 have NANB hepatitis 5 are removed from the screening. So 10 are left
Conclusion: Therefore, about 10 percent of actual donors will still supply NANB-contaminated blood.
It means the 5 people which are removed are replaced by new donors free from NANB hepatits
So how can we inder D ? since the donors remain the same
What's the flaw in my reasoning ?

Author:  aragonn [ 09 Apr 2019, 01:25 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

First, about this line --- It means the 5 people which are removed are replaced by new donors free from NANB hepatits --- this is not mentioned that these 5 will be replaced by new donors. new screening tests are estimated to disqualify up to 5 percent of all prospective blood donors. disqualify does not mean replaced.

2nd we need to --- inferences about the "consequences" of instituting the new tests.

pre-think - My pre-thoughts are --- 10 people will pass, and stay in system. So bank will keep providing contaminated blood or For moral or other issues they will be closed. D is on these lines. Let me know if you need help in eliminating other choices.

Author:  KarishmaB [ 09 Apr 2019, 01:34 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

teaserbae wrote:
AjiteshArun ChiranjeevSingh VeritasKarishma aragonn
As per the question
Let's assume there are 100 people who donate blood
now 15 have NANB hepatitis 5 are removed from the screening. So 10 are left
Conclusion: Therefore, about 10 percent of actual donors will still supply NANB-contaminated blood.
It means the 5 people which are removed are replaced by new donors free from NANB hepatits
So how can we inder D ? since the donors remain the same
What's the flaw in my reasoning ?



There is a problem in the highlighted sentence. How do you figure that they will be replaced by new donors? The argument says "5 percent of all prospective blood donors will be disqualified"
From where will the new donors come?

Author:  pulak1988 [ 12 Sep 2019, 09:27 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

VeritasKarishma wrote:
eybrj2 wrote:
Blood banks will shortly start to screen all donors for NANB hepatitis. Although the new screening tests are estimated to disqualify up to 5 percent of all prospective blood donors, they will still miss two-thirds of donors carrying NANB hepatitis. Therefore, about 10 percent of actual donors will still supply NANB-contaminated blood.

Q) which of the follwoing inferences about the consequences of instituting the new tests is best supported by the passage above?

a) The incidence of new cases of NANB hepatitis is likely to go up by 10 percent.

b) Donations made by patients specifically for their own use are likely to become less frequent.

c) The demand for blood from blood banks is likely to fluctuate more strongly.

d) The blood supplies available from blood banks are likely to go down.

e) The number of prospective first-time donors is likely to go up by 5 percent.


Quote:
At first I picked A thinking, suppose 10 people comprise 2/3rd of the people who carry NABH and donate blood ---> They donate to 10 people at least ---> those people get NABH as well (now NABH must be infectious otherwise why are Blood banks testing to find whether ppl have NABH or not)
So increase of 10 people --> ~ 10% increase in NABH infected people.

After knowing I picked the wrong answer, my fallacy is probably this:
We don't know the total number of NABH infected cases: it may be 20 or it may be 10 ---> supposing it is 20, then 10 people addition is ---> 2% increase not 10% OR if it is 100 cases of infections ---> then it is 10% ----> % increase may be 2-10% or more ---> this makes the option A to be MAY BE TRUE.

A conclusion MUST BE TRUE ---> D) says the blood supplies will decrease ---> YES because people are disqualified, so less blood is available from all the possible donors.

Please do let me know if I am right. And also, How i may improve in ASSUMPTION CR, I also take around 3:30 mins in medium-tough questions.


The problem with (A) is that the argument does not give us enough information to deduce that.

10% of actual donors will supply NANB contaminated blood. But does that mean that all this blood will be used? What if actually only 50% of the blood from a blood bank is used. Then the actual incidence of disease may increase by only 5% (assuming homogenous distribution).
Also, what if NANB infected people are the ones who need blood most often from blood banks. In that case, we may find very few new cases.
Hence, increase in the incidence of disease is a big jump.

(D) is straight forward. 5% fewer people will be able to donate blood due to new tests and that means reduced supply is an effect of the new test.
In inference questions, simpler is usually better.

For discussions on assumption questions, check my blog:
https://www.gmatclub.com/forum/veritas-prep-resource-links-no-longer-available-399979.html/?s=assu ... er&x=0&y=0




I was also about to choose 'd'.

got carried away with the inefcted word of 'A'

Author:  chrtpmdr [ 10 Nov 2019, 06:34 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

I haven't found a clear winner. Isn't this a clear must be true / inference question?

So the stem -> should lead us to an airtight option?

Does the "likely" make the difference here? VeritasKarishma
If the answer choice would say "blood supplies will go down", would that make the answer choice incorrect?

But the adverb "likely" broadens the scope and therefore it is a suitable inference?

Thank you!

Author:  ballest127 [ 05 Dec 2019, 01:14 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

Hi Experts,

I have doubt on D.

Can we readily assume that there will no significantly more people that would like to donate blood?
If it is not the case, the blood supply can still increase.

Please explain.

Thank you.

Author:  GMATNinja [ 05 Dec 2019, 12:15 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

ballest127 wrote:
Hi Experts,

I have doubt on D.

Can we readily assume that there will no significantly more people that would like to donate blood?
If it is not the case, the blood supply can still increase.

Please explain.

Thank you.

The question states, "Which of the following inferences about the consequences of instituting the new tests is best supported by the passage above?" So we don't need to PROVE that (D) is true; as long as the information in the passage supports (D) more than any other choice, we've found our winner. And by POE, we can see that (D) is the best bet.

Also, notice the wording of (D) itself: "The blood supplies available from blood banks are likely to go down." (D) does not say the blood supplies will DEFINITELY go down. The passage suggests that blood supplies will probably go down, so (D) is spot on.

I hope that helps!

Author:  akbgmatter [ 05 Sep 2020, 02:02 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

eybrj2 wrote:
Blood banks will shortly start to screen all donors for NANB hepatitis. Although the new screening tests are estimated to disqualify up to 5 percent of all prospective blood donors, they will still miss two-thirds of donors carrying NANB hepatitis. Therefore, about 10 percent of actual donors will still supply NANB-contaminated blood.

Which of the following inferences about the consequences of instituting the new tests is best supported by the passage above?


A) The incidence of new cases of NANB hepatitis is likely to go up by 10 percent.

B) Donations made by patients specifically for their own use are likely to become less frequent.

C) The demand for blood from blood banks is likely to fluctuate more strongly.

D) The blood supplies available from blood banks are likely to go down.

E) The number of prospective first-time donors is likely to go up by 5 percent.


Project CR Butler:Day 14:Critical Reasoning (CR1)


For all CR butler Questions Click Here



A) The incidence of new cases of NANB hepatitis is likely to go up by 10 percent.
Relationship between donors with NANB and cases isn't given; May be 10 % is utilized by 2%?; Eliminate

B) Donations made by patients specifically for their own use are likely to become less frequent.
Irrelevant; Eliminate

C) The demand for blood from blood banks is likely to fluctuate more strongly.
Fluctuate means go up, down or both. While the demand can go up due to shortage caused by disqualification of 5% donors, other options can't be consequences of the new test. Eliminate.

D) The blood supplies available from blood banks are likely to go down.
Solid option, if the donors go down, then the supplies will go down. Hold.

E) The number of prospective first-time donors is likely to go up by 5 percent.
Goes too far; Eliminate.

D wins!

Author:  Loser94 [ 06 Sep 2020, 12:24 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

inferences about the consequences of instituting the new tests is best supported by the passage


A) The incidence of new cases of NANB hepatitis is likely to go up by 10 percent.
There is no correleation between infected blood and disease occurrence given- Incorrect
B) Donations made by patients specifically for their own use are likely to become less frequent.
How could patients know about the infected blood-OOS incorrect
C) The demand for blood from blood banks is likely to fluctuate more strongly.
Demand depends on requirement which is not effected here-incorrect
D) The blood supplies available from blood banks are likely to go down.
Correct:- supplies can be disturbed due to infected blood storage

E) The number of prospective first-time donors is likely to go up by 5 percent.
First time donors -irrelevant

IMO-D

Author:  rye [ 03 Jan 2021, 16:59 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

VeritasKarishma

Can you please help with providing an Algebraic soln. to the problem?

In my view, the question says 0.95D (D for donor) are potential donors after disqualifying 5% donors.4
Within the 0.95D, 2/3rd are again Heptatitis infected, so 2/3 x 0.95D (= 0.62D) are Heptatitis infected...............(eqn 1)

The question now says, (a part that I am not able to understand) 10% of the Donors (0.1D) shall be Heptatitis infected.........(eqn.2)

But how can 0.62D = 0.1D (from eqn. 1 and eqn2) ?


I will really appreciate a response.

Author:  CEdward [ 07 Feb 2021, 19:31 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

If my math is right, then this is quite a silly example.

Suppose there were 100 donors. 5% reduction amounts to 95 donors. However, 2/3 of donors still submit contaminated blood.

2/3 x 95 = 60 ---> ~60/95 submit contaminated blood.

I don't know where 10% in A came from. Regardless, I will say that the # of individuals who are likely to get Hepatitis in reality would be greater than 10%. So A should be correct unless of course you start positing preventative mechanisms (e.g. additional screening of the blood later on, etc.).

There is ample evidence that shows that contaminated blood leads to Hepatitis (e.g. Hepatitis B).

With respect to Karishma's point:

"10% of actual donors will supply NANB contaminated blood. But does that mean that all this blood will be used? What if actually only 50% of the blood from a blood bank is used"

This confuses the idea between the % of donor blood used and the % of new cases that arise. It's easy to see that even if 50% of the blood was used that the incidence rate will increase by >10%.

Suppose 10 people donated blood and only 5 blood samples were used.

Now suppose the number of new cases hopped from 10-15...that's a 50% increase. A vast oversimplification, mind you.

Author:  Basshead [ 06 Sep 2021, 07:21 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

If 2/3 of the donors supplying contaminated blood = 10% of actual donors, then there will be fewer donations as a result of the screening.

Lets say we have 100 prospective donors. Five of these donors are disqualified.
2/3 of donors carrying NANB hepatitis are missed. So we miss 10 of the donors carrying NANB - contaminated blood.
So 10 out of the 95 donors donated contaminated blood (about 10%, as stated in the conclusion).

A – We can’t infer that new cases will go up
.
B – We can’t infer that these donations are likely to become less frequent.

C – We’re not told anything about demand.

D – CORRECT. If we’re taking less donations, then the blood supplies will likely decrease. We can’t say for certain blood supplies will go down (perhaps more people donate), but it is likely.

E – We don’t know anything about prospective first-time donors.

Author:  Crytiocanalyst [ 11 Sep 2021, 10:48 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

eybrj2 wrote:
Blood banks will shortly start to screen all donors for NANB hepatitis. Although the new screening tests are estimated to disqualify up to 5 percent of all prospective blood donors, they will still miss two-thirds of donors carrying NANB hepatitis. Therefore, about 10 percent of actual donors will still supply NANB-contaminated blood.



Which of the following inferences about the consequences of instituting the new tests is best supported by the passage above?


A) The incidence of new cases of NANB hepatitis is likely to go up by 10 percent.
We are not aware of the previous case scenario therefore we cannot conclusively decide therefore out

B) Donations made by patients specifically for their own use are likely to become less frequent.
This is thoroughly out of context and cannot be infered therefore out

C) The demand for blood from blood banks is likely to fluctuate more strongly.
This may or may not be the case therfore out

D) The blood supplies available from blood banks are likely to go down.
This can be the case since new screening methods are introduced it may lead to decreased cases

E) The number of prospective first-time donors is likely to go up by 5 percent.
This cannot be infered from the passage therefore out

Therefore IMO D

Author:  ritzu [ 01 Jul 2022, 18:12 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

Blood banks will shortly start to screen all donors for NANB hepatitis.
the new screening tests will disqualify upto 5 percent of all prospective blood donors,
Blood banks will still miss two-thirds of donors carrying NANB hepatitis.
Therefore, about 10 percent of actual donors will still supply NANB-contaminated blood.

Which of the following inferences about the consequences of instituting the new tests is best supported by the passage above?

A) The incidence of new cases of NANB hepatitis is likely to go up by 10 percent.: we dont know if this will happen.

B) Donations made by patients specifically for their own use are likely to become less frequent.: outside information. cannot verify.

C) The demand for blood from blood banks is likely to fluctuate more strongly.: we can make convoluted stories in our heads about this. for example: the test will not be able to disqualify 10% of the donors. this will increase the no of cases - more people might need blood later, etc.

but: up until this point, no test was made and everyone donated blood. which means that people were always donating contaminated blood but the impact is not know. we dont know what will happen if people donate contaminated blood because thats beyond the scope of the passage.

D) The blood supplies available from blood banks are likely to go down.: yes because before 100% people were accepted and now 95% are accepted which is a decrease of 5%. simple and straightforward.

E) The number of prospective first-time donors is likely to go up by 5 percent.: we dont know about first time donors. this is out of the scope of the question.

Author:  aumd568 [ 03 Aug 2022, 23:05 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

Hi AndrewN,

Everyone here is saying that Option (A) is not really implied.

I eliminated Option (A) since if anything it is a preventive measure. The old method had 15%, now we have 10% so the phrase "likely to go up" really looked wrong to me which is why I eliminated Option (A).

Does that make sense?

Thanks.

-Aum

Author:  nazii [ 13 Nov 2022, 13:37 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

@e gmat
would you pls help I can't understand at all

Author:  egmat [ 28 Nov 2022, 00:24 ]
Post subject:  Re: Blood banks will shortly start to screen all donors for NANB hepatitis

nazii wrote:
@e gmat
would you pls help I can't understand at all


Hey nazii,

I can help with this one!

This is a question that really tests us on our ability to visualize sentences (this is particularly true of the answer choices!).

Here is a video I made that may help provide clarity.


Hope this helps!
Harsha

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