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

It is currently 17 Jun 2019, 00:19

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

In a freshman biochemistry class at Newton University, the teacher

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

Hide Tags

 
Manager
Manager
User avatar
Status: Perspiring
Joined: 15 Feb 2012
Posts: 86
Concentration: Marketing, Strategy
GPA: 3.6
WE: Engineering (Computer Software)
GMAT ToolKit User
In a freshman biochemistry class at Newton University, the teacher  [#permalink]

Show Tags

New post 24 Jul 2015, 09:51
11
00:00
A
B
C
D
E

Difficulty:

  75% (hard)

Question Stats:

57% (02:06) correct 43% (02:07) wrong based on 763 sessions

HideShow timer Statistics

In a freshman biochemistry class at Newton University, the teacher assigns the class only ‘A’s, ‘B’s’ or ‘C’s. The average on the semester final for the class of 2012 was five points lower than that of the class of 2011. Therefore, the percent of students who received ‘C’s was greater in 2012 than in 2011.

Which of the following, if true, suggests the conclusion above is not necessarily valid?

There was a greater number of students in the 2011 class than in the 2012 class.
The percent of students who received ‘A’s in 2011 was less than in 2012.
Five more students received ‘A’s in 2012 than in 2011.
The same number of students received ‘B’s in 2011 as in 2012.
The percent of students who received ‘B’s was greater in 2012 than in 2011.
Most Helpful Expert Reply
Veritas Prep GMAT Instructor
User avatar
D
Joined: 16 Oct 2010
Posts: 9325
Location: Pune, India
Re: In a freshman biochemistry class at Newton University, the teacher  [#permalink]

Show Tags

New post 29 Jan 2019, 08:42
1
NickHalden wrote:
In a freshman biochemistry class at Newton University, the teacher assigns the class only ‘A’s, ‘B’s’ or ‘C’s. The average on the semester final for the class of 2012 was five points lower than that of the class of 2011. Therefore, the percent of students who received ‘C’s was greater in 2012 than in 2011.

Which of the following, if true, suggests the conclusion above is not necessarily valid?

There was a greater number of students in the 2011 class than in the 2012 class.
The percent of students who received ‘A’s in 2011 was less than in 2012.
Five more students received ‘A’s in 2012 than in 2011.
The same number of students received ‘B’s in 2011 as in 2012.
The percent of students who received ‘B’s was greater in 2012 than in 2011.



There are three grades A, B and C.
The average score was 5 points lower in 2012 than in 2011

Conclusion: Percent of students who got Cs was greater in 2012 than in 2011

Because the average score is lower, the assumption is that more percentage of people got Cs. So it doesn't matter how many people are there in either year. We are talking about the average score and the percentage of students.

We want to weaken the conclusion.

(A) There was a greater number of students in the 2011 class than in the 2012 class.

This, as we discussed above, is irrelevant.

(B) The percent of students who received ‘A’s in 2011 was less than in 2012.

Percent of students who got A in 2012 > Percent of students who got A in 2011
Since average score is lower, more percent of students who got A means more percent of students got C.
Grade A might be given to students getting more than average (simply speaking). If there are more such people, then there will be more people who will get less than average (and hence grade C) to get to the average.

Say these are the scores of 5 people:
3 4 4 4 5

If you have more people getting 5, a higher score, you will need more people to get 3 too to make up the average of 4:
3 3 4 5 5

So option (B) makes our conclusion more likely, not less.

(C) Five more students received ‘A’s in 2012 than in 2011.

Again, numbers are irrelevant.

(D) The same number of students received ‘B’s in 2011 as in 2012.

Numbers are irrelevant.

(E) The percent of students who received ‘B’s was greater in 2012 than in 2011

Even though the average is lower, more percent of students received B's. It is possible that the lower score still gives a B.
IF more people get B (around average), fewer people will get both A's and C's.

Say initially, the scores looked like this: 3 3 4 5 5

If students at average increase, it may look like this: 3 4 4 4 5

Hence percentage of C's may actually decrease.

This weakens our conclusion.

Answer (E)
_________________
Karishma
Veritas Prep GMAT Instructor

Learn more about how Veritas Prep can help you achieve a great GMAT score by checking out their GMAT Prep Options >
General Discussion
Intern
Intern
avatar
Joined: 12 Jan 2015
Posts: 14
Concentration: Entrepreneurship, Human Resources
GMAT Date: 06-27-2015
Re: In a freshman biochemistry class at Newton University, the teacher  [#permalink]

Show Tags

New post 24 Jul 2015, 12:21
Can anyone shed some light on why the OA is E?
Director
Director
User avatar
G
Joined: 23 Jan 2013
Posts: 547
Schools: Cambridge'16
Re: In a freshman biochemistry class at Newton University, the teacher  [#permalink]

Show Tags

New post 24 Jul 2015, 22:05
The average score relates to weighted mean concept:

A*x+B*y+C*z/x+y+z, where x,y,z is the percent of every type of students (i.e A,B,C). If z is more we get increase of average, if x OR y is more we get decrease

Conclusion says that in 2012 av. score 5 point less than in 2011 because more C. What is the alternative reason?

A. There was a greater number of students in the 2011 class than in the 2012 class. (It doesn't matter, we are interested only in percemt of every type of students)

B. The percent of students who received ‘A’s in 2011 was less than in 2012. (If so, av. score in 2012 could be higher)

C. Five more students received ‘A’s in 2012 than in 2011. (We do not know the percentage, so out of scope)

D.The same number of students received ‘B’s in 2011 as in 2012. (Again, no percentage, out of scope)

E. The percent of students who received ‘B’s was greater in 2012 than in 2011 (It fits the concept)

E
Intern
Intern
avatar
Joined: 06 Mar 2013
Posts: 38
Re: In a freshman biochemistry class at Newton University, the teacher  [#permalink]

Show Tags

New post 25 Jul 2015, 04:27
The first four options can be eliminated based on the reasons given by Temurkhon.

Option E is correct because if more students received a B as compared to the previous year, then the average could go down. So, that is another possible reason instead of the conclusion given in the argument.

Hope this helps :)
_________________
Best Regards!

Consider +1 KUDOS if you find this post useful
Current Student
avatar
B
Joined: 08 Jan 2015
Posts: 80
Location: Thailand
GMAT 1: 540 Q41 V23
GMAT 2: 570 Q44 V24
GMAT 3: 550 Q44 V21
GMAT 4: 660 Q48 V33
GPA: 3.31
WE: Science (Other)
Re: In a freshman biochemistry class at Newton University, the teacher  [#permalink]

Show Tags

New post 27 Jul 2015, 00:04
Is this kind of question appear in CR when I take the real test?

I doubt it
Manhattan Prep Instructor
User avatar
Joined: 30 Apr 2012
Posts: 792
Re: In a freshman biochemistry class at Newton University, the teacher  [#permalink]

Show Tags

New post 31 Jul 2015, 05:48
1
I'm responding to a PM on this one.

The question is a weakening question because it is looking for information that would make the conclusion less valid. It's not typical of a question you would see on the real test, but it does highlight logic errors that you will see on the real test. The test loves to transition between number and percentage on the real test, and this question does a good job of testing that issue.

If you can understand the logic of the argument and can reason through the answers to see which one would weaken the conclusion, you have skills that would serve you well on the exam...

KW
_________________
Intern
Intern
avatar
Joined: 22 Jul 2015
Posts: 18
GMAT 1: 760 Q49 V45
GPA: 3.92
Re: In a freshman biochemistry class at Newton University, the teacher  [#permalink]

Show Tags

New post 31 Jul 2015, 11:47
Came for the title of the problem - nicely done!
Manhattan Prep Instructor
User avatar
Joined: 30 Apr 2012
Posts: 792
Re: In a freshman biochemistry class at Newton University, the teacher  [#permalink]

Show Tags

New post 08 Aug 2015, 10:22
BicepBrachii wrote:
Came for the title of the problem - nicely done!


I didn't even see the title the first time around. That is classic.
_________________
Intern
Intern
avatar
S
Joined: 17 May 2015
Posts: 28
Re: In a freshman biochemistry class at Newton University, the teacher  [#permalink]

Show Tags

New post 13 Nov 2015, 03:03
KyleWiddison wrote:
I'm responding to a PM on this one.

The question is a weakening question because it is looking for information that would make the conclusion less valid. It's not typical of a question you would see on the real test, but it does highlight logic errors that you will see on the real test. The test loves to transition between number and percentage on the real test, and this question does a good job of testing that issue.

If you can understand the logic of the argument and can reason through the answers to see which one would weaken the conclusion, you have skills that would serve you well on the exam...

KW



Why is it not a typical GMAT Question? It looks like a typical one to me . My following question is if its a 700+ Question. I think its 600 level Question. Please advice
Manhattan Prep Instructor
User avatar
Joined: 30 Apr 2012
Posts: 792
Re: In a freshman biochemistry class at Newton University, the teacher  [#permalink]

Show Tags

New post 21 Nov 2015, 08:41
1
What I'm getting at here is that it's from a prep company, not the actual GMAT. We do our best to approximate the GMAT, but it's not the same. This particular problem points out an issue that you will see tested on the GMAT, but the GMAT is typically more subtle than this...

As far as the difficulty, it's super hard to determine. Based on the performance of the people taking this one I would probably peg this as a high 600 level...

KW
_________________
Board of Directors
User avatar
P
Joined: 17 Jul 2014
Posts: 2548
Location: United States (IL)
Concentration: Finance, Economics
GMAT 1: 650 Q49 V30
GPA: 3.92
WE: General Management (Transportation)
GMAT ToolKit User Reviews Badge
Re: In a freshman biochemistry class at Newton University, the teacher  [#permalink]

Show Tags

New post 05 Feb 2016, 19:56
NickHalden wrote:
In a freshman biochemistry class at Newton University, the teacher assigns the class only ‘A’s, ‘B’s’ or ‘C’s.
The average on the semester final for the class of 2012 was five points lower than that of the class of 2011.
Therefore, the percent of students who received ‘C’s was greater in 2012 than in 2011.

Which of the following, if true, suggests the conclusion above is not necessarily valid?

There was a greater number of students in the 2011 class than in the 2012 class.
The percent of students who received ‘A’s in 2011 was less than in 2012.
Five more students received ‘A’s in 2012 than in 2011.
The same number of students received ‘B’s in 2011 as in 2012.
The percent of students who received ‘B’s was greater in 2012 than in 2011.


woah..question from hell...
we speak about absolute values, thus, we can eliminate C and D right away, as we do not know what portion of the whole - the numbers given represent.
A - doesn't tell much. for ex. in 2011 - 100 students, and in 2012 - 10 students. for ex. in 2011 - 10 students got C, and in 2012 - 2 student got C. the conclusion still hold true, as in 2012 - 20% got C, while in 2011 - 10% only.
B - if in 2011 the % of A was less than in 2012, then it means that in 2012 more C's would have been, otherwise a drop of 5 points could not have been explained.
E - the only one that weakens the conclusion. for example. in 2011 we had 100 students, all got A. in 2012, we got 100 students, 90 got A, while 10 got B. we clearly see that the average would drop, while no C's at all were registered.
Intern
Intern
avatar
B
Joined: 05 Apr 2018
Posts: 17
CAT Tests
Re: In a freshman biochemistry class at Newton University, the teacher  [#permalink]

Show Tags

New post 19 Jan 2019, 06:58
I find this question specific to countries that have the system that uses letters. How can I understand the correlation between letters and numbers?

Posted from my mobile device
Manager
Manager
User avatar
S
Joined: 21 Jul 2018
Posts: 193
Reviews Badge
Re: In a freshman biochemistry class at Newton University, the teacher  [#permalink]

Show Tags

New post 22 Jan 2019, 06:30
popovarseniy wrote:
I find this question specific to countries that have the system that uses letters. How can I understand the correlation between letters and numbers?

Posted from my mobile device


Hi popovarseniy

I don't think one need to go in depth to find exact correlation between letters and numbers as this is neither a quant question nor they are asking you answer in accurate numbers, You just have to assume that higher number student will get A and lower will C.

Hope it helps !

Thanks !
_________________
______________________________
Press +1 Kudos if my post helped you a little and help me to ulcock the tests ;) Wish you all success

I'd appreciate learning about the grammatical errors in my posts


Please let me know if I'm wrong somewhere and help me to learn :-)
Manager
Manager
User avatar
G
Joined: 21 Jun 2017
Posts: 234
Concentration: Finance, Economics
WE: Corporate Finance (Commercial Banking)
In a freshman biochemistry class at Newton University, the teacher  [#permalink]

Show Tags

New post Updated on: 29 Jan 2019, 09:43
B and E both sound same to me. If A decrases, B or C could be manipulated accordingly. Please explain the quant behind both the options.


Regards
_________________
Even if it takes me 30 attempts, I am determined enough to score 740+ in my 31st attempt. This is it, this is what I have been waiting for, now is the time to get up and fight, for my life is 100% my responsibility.

Dil ye Ziddi hai !!!

Originally posted by ShankSouljaBoi on 28 Jan 2019, 08:46.
Last edited by ShankSouljaBoi on 29 Jan 2019, 09:43, edited 1 time in total.
examPAL Representative
User avatar
P
Joined: 07 Dec 2017
Posts: 1072
Re: In a freshman biochemistry class at Newton University, the teacher  [#permalink]

Show Tags

New post 29 Jan 2019, 02:08
1
ShankSouljaBoi wrote:
B and E both sound same to me. If A decrases B or C could be manipulated accordingly. Please explain the quant behind boththe options.


Regards


Let's say there are 3 students in the class.
E tells us that is 2012, more received B's: so, for example we could have 3 B's in 2012 and 3 A's in 2011. Higher average in 2011, no change in % of C's. Conclusion not valid!
B tells us in 2012 we had more A's. But since we know the overall average in 2012 is lower, there must be more c's: for example: 2012 - 1 A, 2 C's, 2011 - 3 B's. Average higher in 2011, conclusion still valid... not our answer
_________________
GMAT Club Bot
Re: In a freshman biochemistry class at Newton University, the teacher   [#permalink] 29 Jan 2019, 02:08
Display posts from previous: Sort by

In a freshman biochemistry class at Newton University, the teacher

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


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