GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 18 Aug 2018, 14:57

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

Blood banks will shortly start to screen all donors for NANB hepatitis

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Manager
Manager
avatar
Joined: 16 Jul 2009
Posts: 223
Blood banks will shortly start to screen all donors for NANB hepatitis  [#permalink]

Show Tags

New post Updated on: 22 May 2018, 03:11
13
53
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

34% (01:45) correct 66% (02:06) wrong based on 1841 sessions

HideShow timer Statistics

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.

The argument above depends on which of the following assumptions?


(A) Donors carrying NANB hepatitis do not, in a large percentage of cases, carry other infections for which reliable screening tests are routinely performed.

(B) Donors carrying NANB hepatitis do not, in a large percentage of cases, develop the disease themselves at any point.

(C) The estimate of the number of donors who would be disqualified by tests for NANB hepatitis is an underestimate.

(D) The incidence of NANB hepatitis is lower among the potential blood donors than it is in the population at large.

(E) The donors who will still supply NANB-contaminated blood will donate blood at the average frequency for all donors

Originally posted by abhi758 on 14 Aug 2009, 13:18.
Last edited by Bunuel on 22 May 2018, 03:11, edited 1 time in total.
Renamed the topic and edited the question.
Most Helpful Expert Reply
MBA Section Director
User avatar
V
Joined: 19 Mar 2012
Posts: 5121
Location: India
GMAT 1: 760 Q50 V42
GPA: 3.8
WE: Marketing (Non-Profit and Government)
#Top150 CR: Blood banks will shortly start to screen all donors  [#permalink]

Show Tags

New post 04 Dec 2015, 09:30
2
9
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.

The argument above depends on which of the following assumptions?

A. Donors carrying NANB hepatitis do not, in a large percentage of cases, carry other infections for which reliable screening tests are routinely performed.

B. Donors carrying NANB hepatitis do not, in a large percentage of cases, develop the disease themselves at any point.

C. The estimate of the number of donors who would be disqualified by tests for NANB hepatitis is an underestimate.

D. The incidence of NANB hepatitis is lower among the potential blood donors than it is in the population at large.

E. The donors who will still supply NANB-contaminated blood will donate blood at the average frequency for all donors
_________________

Have an MBA application Question? ASK ME ANYTHING!

My Stuff: Four Years to 760 | MBA Trends for Indian Applicants

My GMAT Resources
V30-V40: How to do it! | GMATPrep SC | GMATPrep CR | GMATPrep RC | Critical Reasoning Megathread | CR: Numbers and Statistics | CR: Weaken | CR: Strengthen | CR: Assumption | SC: Modifier | SC: Meaning | SC: SV Agreement | RC: Primary Purpose | PS/DS: Numbers and Inequalities | PS/DS: Combinatorics and Coordinates

My MBA Resources
Everything about the MBA Application | Over-Represented MBA woes | Fit Vs Rankings | Low GPA: What you can do | Letter of Recommendation: The Guide | Indian B Schools accepting GMAT score | Why MBA?

My Reviews
Veritas Prep Live Online

Most Helpful Community Reply
Intern
Intern
User avatar
S
Joined: 18 May 2014
Posts: 31
Location: India
GMAT 1: 710 Q49 V40
GPA: 3.8
Reviews Badge
Re: Blood banks will shortly start to screen all donors for NANB hepatitis  [#permalink]

Show Tags

New post 17 May 2015, 08:47
23
6
Meaning of the question :

Let there be 100 people(all prospective blood donors) -> so 5 people will be caught in the new test.

2/3 * (people carrying nanb) = missed

therefore 1/3 * (people carrying nanb) = those that were caught = 5

therefore, people carrying nanb = 5*3 = 15

missed people = 10 (15-5) -> this is 10% of the prospective donor and the conclusion that they will still supply contaminated blood


Conclusion : 10% of actual donors will still supply NANB-contaminated blood


Now if donors carrying nanb carry other infections for which tests are routinely performed -> then the number of people carrying

nanb (with other infection) will be caught and will be less in number.

Thus, 2/3 * (people carrying nanb) -> will be less -> those missed will be less -> then we cannot claim that 10% of the donors will

still supply contaminated blood.
General Discussion
Senior Manager
Senior Manager
User avatar
Joined: 26 Jul 2009
Posts: 316
Re: Blood banks will shortly start to screen all donors for NANB hepatitis  [#permalink]

Show Tags

New post 16 Aug 2009, 20:28
3
Tough one.

My explanation:

If NANB carries other infections which can be tested true positive (or reliable as stated in Option A), then the chance of detecting NANB will be higher. However, Option A states that this is not the case. Hence the 2/3 of NANB will still be missed and this figure (2/3) has to be taken as accurate. Thus its a necessary assumption.
Director
Director
User avatar
Joined: 25 Aug 2007
Posts: 831
WE 1: 3.5 yrs IT
WE 2: 2.5 yrs Retail chain
Re: Blood banks will shortly start to screen all donors for NANB hepatitis  [#permalink]

Show Tags

New post 07 May 2010, 02:45
2
1
Hi,

I solved this question with a different approach. I hope you will find it useful:

The premises are all seemed peculiar to me. But, I used %age and Number to solve this.

Conclusion is on ACTUAL 10% donors, which is nowhere mentioned in the argument. So, we need to look for following as per CR Bible:
1. Options which have ACTUAL keyword.
2. Options involveing %age instead of numbers, as we are given %ages only. So, choice with numbers will be Incorrect.
3. There seems to logical gaps in the argument and the author mentioned strong words to indicate that his reasoning is air-tight, which points to a DEFENDER assumption case. So, look for negative answer choices, which involve some defending language.

abhi758 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.

The argument above depends on which of the following assumptions?
(A) Donors carrying NANB hepatitis do not, in a large percentage of cases, carry other infections for which reliable screening tests are routinely performed.
(B) Donors carrying NANB hepatitis do not, in a large percentage of cases, develop the disease themselves at any point. [The conclusion is not based on this assumption. It fails to meet above three conditions and not even the negation technique proves this as an ssumption. Incorrect]
(C) The estimate of the number of donors who would be disqualified by tests for NANB hepatitis is an underestimate. [It fails to meet the (2) point above. color=#FF0000]Incorrect[/color]]
(D) The incidence of NANB hepatitis is lower among the potential blood donors than it is in the population at large. [It fails to meet the (2) point above and also comparing with the population as a whole, which is irrelevent. Incorrect]
(E) The donors who will still supply NANB-contaminated blood will donate blood at the average frequency for all donors. [This is irrelevant to the conclusion. Try the negation test. The conclusion will still be intact. Incorrect]

Kindly explain your answers..

_________________

Want to improve your CR: http://gmatclub.com/forum/cr-methods-an-approach-to-find-the-best-answers-93146.html
Tricky Quant problems: http://gmatclub.com/forum/50-tricky-questions-92834.html
Important Grammer Fundamentals: http://gmatclub.com/forum/key-fundamentals-of-grammer-our-crucial-learnings-on-sc-93659.html

Retired Moderator
avatar
B
Joined: 16 Nov 2010
Posts: 1458
Location: United States (IN)
Concentration: Strategy, Technology
Premium Member Reviews Badge
Re: Blood banks will shortly start to screen all donors  [#permalink]

Show Tags

New post 20 Mar 2011, 04:32
1
1
Answer - A) Donors carrying NANB hepatitis do not, in a large percentage of cases, carry other infections for which reliable screening tests are routinely performed

So they'll escape the screening here, and the other screenings also, hence the number of infected donors who did not get filtered out does not change.

Say there are 15% donors affected, so 2/3 * 15 escape, hence 10% remain, they don't get caught in any other test so the %age is constant.
_________________

Formula of Life -> Achievement/Potential = k * Happiness (where k is a constant)

GMAT Club Premium Membership - big benefits and savings

Manager
Manager
avatar
Joined: 25 Dec 2012
Posts: 123
Re: Blood banks will shortly start to screen all donors for NANB hepatitis  [#permalink]

Show Tags

New post 17 Nov 2014, 20:18
1
1
abhi758 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.

The argument above depends on which of the following assumptions?

(A) Donors carrying NANB hepatitis do not, in a large percentage of cases, carry other infections for which reliable screening tests are routinely performed.
(B) Donors carrying NANB hepatitis do not, in a large percentage of cases, develop the disease themselves at any point.
(C) The estimate of the number of donors who would be disqualified by tests for NANB hepatitis is an underestimate.
(D) The incidence of NANB hepatitis is lower among the potential blood donors than it is in the population at large.
(E) The donors who will still supply NANB-contaminated blood will donate blood at the average frequency for all donors

Kindly explain your answers..


Derived 'A' through POE.

Understanding of the passage.
P1 - Screening is happening.
P2 - Able to restrict only 5% out of 15%
C1 - Still 10% of ppl r giving the contaminated blood.

Assumption made - Some issue is there bcos of transfering this contaminated blood, Hence screening is happening in all the blood donors.

B - Donors carrying NANB hepatitis do not, in a large percentage of cases, develop the disease themselves at any point. The information provided is not creating any link between the premise and conclusion. Also, if its not going to have any effect or creating any disease then why the screening is happening.
(C) The estimate of the number of donors who would be disqualified by tests for NANB hepatitis is an underestimate. - The statement has been already stated in the main Argument. Only 1/3rd was being identified.
(D) The incidence of NANB hepatitis is lower among the potential blood donors than it is in the population at large. - Complete Out of scope. Blood Donor Vs Total Population
(E) The donors who will still supply NANB-contaminated blood will donate blood at the average frequency for all donors Again its a statement or an information which no way supports the argument. Its a mere inforation. What ever frequecny they are giving it doesnt support the Conclusion made

So Finally A. A is ok with the pre assumption made during reading the argument. We are only checking for NANB, what if any other contamination is there? Through POE and pre assumption i reached A.

A is better choice among the 5.
Manager
Manager
avatar
Joined: 17 Aug 2015
Posts: 99
Location: India
Concentration: Strategy, General Management
Schools: Duke '19 (II)
GMAT 1: 750 Q49 V42
GPA: 4
WE: Information Technology (Investment Banking)
GMAT ToolKit User
Re: Blood banks will shortly start to screen all donors for NANB hepatitis  [#permalink]

Show Tags

New post 02 Sep 2015, 04:17
1
1
I initially replied (E) incorrectly. Here's the explanation of why it is (A) -

abhi758 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.

Note - 5% corr. to 1/3, so 10% corr to the remaining 2/3 who have NANB and are missed in screening.

The argument above depends on which of the following assumptions?

(A) Donors carrying NANB hepatitis do not, in a large percentage of cases, carry other infections for which reliable screening tests are routinely performed.
If this were not the case, some donors with NANB who also have other infections would be disqualified by the screening for the other infection. So, the 10% figure would change. On the other hand, if a negligible % of NANB folks carry other infections, the 10% figure wouldn't change much.

(B) Donors carrying NANB hepatitis do not, in a large percentage of cases, develop the disease themselves at any point.
Whether NANB carriers develop the disease is irrelevant to their donation of blood.
(C) The estimate of the number of donors who would be disqualified by tests for NANB hepatitis is an underestimate.
This is somewhat tough. Assume it is not an underestimate. If it is an accurate estimate, the given numbers are true and this assumption is not needed. If it is an overestimate, more than 1/3rd of donors would be disqualified. So, LESS than 10% would pass through. In the first case, the assumption is not necessary. In the second case, it actively contradicts the argument.
(D) The incidence of NANB hepatitis is lower among the potential blood donors than it is in the population at large.
Irrelevant. We have statistics for NANB already. Why bother about the rest of the population?
(E) The donors who will still supply NANB-contaminated blood will donate blood at the average frequency for all donors
This is the toughest. Here, one could argue that if NANB carriers donate blood, say, 10x more frequently as compared to uninfected patients, they would cause 10x more blood contamination. HOWEVER, this would apply if the argument argued for about 10% of BLOOD CONTAMINATION. Instead, the argument argues for the percentage of DONORS THEMSELVES. Even if one NANB donor donates 10x times, he will still be counted as a single donor.
Kindly explain your answers..


Great question. Thanks for posting.
_________________

If you like this post, be kind and help me with Kudos!

Cheers!

Manager
Manager
avatar
B
Joined: 07 Jun 2015
Posts: 85
WE: Design (Aerospace and Defense)
Re: Blood banks will shortly start to screen all donors for NANB hepatitis  [#permalink]

Show Tags

New post 25 Oct 2015, 02:25
1
Quote:
(A) Donors carrying NANB hepatitis do not, in a large percentage of cases, carry other infections for which reliable screening tests are routinely performed.


It is already explained in the passage that 2/3rd of the NANB donors will not be detected.That means the current tests available for the NANB infection is not flawless. So the only chance is that,for NANB to be detected, they should have some other infectious disease(for which a flawless test is available) which occur along with NANB so that detection of the other disease will lead to elimination of NANB donor.This is what the logic given in option A.
BSchool Forum Moderator
User avatar
D
Joined: 28 Mar 2017
Posts: 1102
Location: India
GMAT 1: 730 Q49 V41
GPA: 4
CAT Tests
Re: #Top150 CR: Blood banks will shortly start to screen all donors  [#permalink]

Show Tags

New post 04 Jan 2018, 10:24
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.

The argument above depends on which of the following assumptions?

A. Donors carrying NANB hepatitis do not, in a large percentage of cases, carry other infections for which reliable screening tests are routinely performed. -Correct. If these people have other diseases that are easily identifiable then they will be barred from blood donation.

B. Donors carrying NANB hepatitis do not, in a large percentage of cases, develop the disease themselves at any point. -Whether they develop the diseases is out of scope because having NANB virus will make them ineligible for blood donation, if caught in the test.

C. The estimate of the number of donors who would be disqualified by tests for NANB hepatitis is an underestimate. -Let it be an underestimation for we know 10% infected people will donate blood.

D. The incidence of NANB hepatitis is lower among the potential blood donors than it is in the population at large. -Out of scope

E. The donors who will still supply NANB-contaminated blood will donate blood at the average frequency for all donors -Still it doesn't clear whether 10% will donate or not.
_________________

Kudos if my post helps!

Long And A Fruitful Journey - V21 to V41; If I can, So Can You!!


Preparing for RC my way


My study resources:
1. Useful Formulae, Concepts and Tricks-Quant
2. e-GMAT's ALL SC Compilation
3. LSAT RC compilation
4. Actual LSAT CR collection by Broal
5. QOTD RC (Carcass)
6. Challange OG RC
7. GMAT Prep Challenge RC

Manager
Manager
User avatar
S
Joined: 23 May 2017
Posts: 244
Concentration: Finance, Accounting
WE: Programming (Energy and Utilities)
Re: #Top150 CR: Blood banks will shortly start to screen all donors  [#permalink]

Show Tags

New post 04 Jan 2018, 13:02
"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.
"

Isn't the correct answer choice attacking the given premise. we are given that 2/3rd will be missed. How can we attack the given fact in the argument.


A. Donors carrying NANB hepatitis do not, in a large percentage of cases, carry other infections for which reliable screening tests are routinely performed.

if this is true, our premise doesn't stand.


I was actually hoping to see the link between donors and actual donors.
_________________

If you like the post, please award me Kudos!! It motivates me

examPAL Representative
User avatar
B
Joined: 01 Mar 2017
Posts: 117
Re: #Top150 CR: Blood banks will shortly start to screen all donors  [#permalink]

Show Tags

New post 04 Jan 2018, 14:43
1
Leo8 wrote:
"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.
"

Isn't the correct answer choice attacking the given premise. we are given that 2/3rd will be missed. How can we attack the given fact in the argument.


A. Donors carrying NANB hepatitis do not, in a large percentage of cases, carry other infections for which reliable screening tests are routinely performed.

if this is true, our premise doesn't stand.


I was actually hoping to see the link between donors and actual donors.


Leo8 it doesn't contradict our premise. We are asked which answer strengthens the premise that 2/3 of NANB donors will not be disqualified. One thing that is necessary for this is that those 2/3 won't be disqualified for any other reason - which is exactly what A tells us.
Is this clear, or still confusing? Why do you think the premise doesn't stand?
_________________

Dave Green
Senior tutor at examPAL
Signup for a free GMAT course
Image
Image

examPAL Representative
User avatar
B
Joined: 01 Mar 2017
Posts: 117
Re: #Top150 CR: Blood banks will shortly start to screen all donors  [#permalink]

Show Tags

New post 04 Jan 2018, 15:01
1
souvik101990 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.

The argument above depends on which of the following assumptions?

A. Donors carrying NANB hepatitis do not, in a large percentage of cases, carry other infections for which reliable screening tests are routinely performed.

B. Donors carrying NANB hepatitis do not, in a large percentage of cases, develop the disease themselves at any point.

C. The estimate of the number of donors who would be disqualified by tests for NANB hepatitis is an underestimate.

D. The incidence of NANB hepatitis is lower among the potential blood donors than it is in the population at large.

E. The donors who will still supply NANB-contaminated blood will donate blood at the average frequency for all donors



Logically, we are given an assumption (the test will miss 2/3 of NANB donors) and a conclusion (2/3 of NANB donors, or 10% of all donors, will not be disqualified). But notice this assumes those infected won't be disqualified for any OTHER reason than NANB either - which is what A suggests.

By process of elimination:
A - Yes! this means if they aren't detected for NANb, they won't be detected for anything else.
B - irrelevant
C - this contradicts the argument, it doesn't underline it
D - not relevant: the stats we were given are about the potential donors, not the population at large
E - we don't know anything about the average frequency of donors, so this is just a distraction.
_________________

Dave Green
Senior tutor at examPAL
Signup for a free GMAT course
Image
Image

Manager
Manager
avatar
B
Joined: 19 Jun 2017
Posts: 57
Location: India
GPA: 3.23
Re: #Top150 CR: Blood banks will shortly start to screen all donors  [#permalink]

Show Tags

New post 10 Jan 2018, 12:43
I couldnt understand the conclusion correctly. please explain
Intern
Intern
avatar
S
Joined: 18 Jun 2017
Posts: 28
#Top150 CR: Blood banks will shortly start to screen all donors  [#permalink]

Show Tags

New post 14 Apr 2018, 08:31
hi sahilsnpt,


the way i understood this argument is,
Considering sample size of 60 people who are donating blood.
among whom 5% disqualified because they have NAMB in their blood i.e. 3 are disqualified.
Further argument says, screening misses 2/3rd means it has caught 1/3rd of NAMB cases (1/3*x=3)
i.e. Total NAMB cases are 9 and 6 are missed cases.

6 are the people who have passed the screening despite having NAMB.
So conclusion correctly says 10% of 60(Total) i.e 6 will supply contaminated blood.


We want to break this conclusion by negating options.
option A on negation says- Donors carrying NANB hepatitis carry other infections for which reliable screening tests are routinely performed.
Means out of 6 who managed to get through new screening will fail some other screening like of other blood test criteria and that number 10% (say 6) will be reduced.
And few people despite having NAMB and having passed NAMB screening will go ahead with donation.
As this reasoning breaks conclusion. It must be the right choice.
#Top150 CR: Blood banks will shortly start to screen all donors &nbs [#permalink] 14 Apr 2018, 08:31
Display posts from previous: Sort by

Blood banks will shortly start to screen all donors for NANB hepatitis

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  

Events & Promotions

PREV
NEXT


GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.