NEW HERE? LEARN MORE
closeclose
Last visit was: 25 Apr 2024, 20:27 It is currently 25 Apr 2024, 20:27
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

10 students took a chemistry exam that was graded on a scale

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
avatar
ace001
Intern
Intern
Joined: 30 Jun 2010
Posts: 1
Own Kudos [?]: 49 [49]
Given Kudos: 0
Send PM
10 students took a chemistry exam that was graded on a scale [#permalink] New post   30 Jun 2010, 20:00
3
Kudos
45
Bookmarks
00:00
A
B
C
D
E

Difficulty:

25% (medium)

Question Stats:

79% (01:52) correct 21% (01:57) wrong based on 1105 sessions
Hide Show timer Statistics
10 students took a chemistry exam that was graded on a scale of 0 to 100. Five of the students were in Dr. Adams’ class and the other five students were in Dr. Brown’s class. Is the median score for Dr. Adams’ students greater than the median score for Dr. Brown’s students?

(1) The range of scores for students in Dr. Adams’ class was 40 to 80, while the range of scores for students in Dr. Brown’s class was 50 to 90.

(2) If the students are paired in study teams such that each student from Dr. Adams’ class has a partner from Dr. Brown’s class, there is a way to pair the 10 students such that the higher scorer in each pair is one of Dr. Brown’s students.
ShowHide Answer
Official Answer
B
Most Helpful Reply
avatar
parker
Manhattan Prep Instructor
Joined: 29 Apr 2010
Posts: 113
Own Kudos [?]: 1807 [25]
Given Kudos: 1
Send PM
Re: 10 students took a chemistry exam that was graded on a scale [#permalink] New post   30 Jun 2010, 22:39
14
Kudos
11
Bookmarks
Expert Reply
This is a Yes/No Data Sufficiency question that never requires you to identify the specific values of the medians-- just to answer a question about their relative values.

Remember that the median--as opposed to the mean--only depends on the value of the middle term (or 2 middle terms if you have an even number of elements in your list, but each class has an odd number of students here) when all the terms are listed in order. For example:

For the set {1, 1, 1, 2, 100} -- median = 1
For the set {1, 1, 1, 1, 1} -- median = 1
For the set {-1000, -100, 1, 20, 99999}-- yup, median still equals 1.

Statement 1 tells you about the RANGE of scores in class A(dams). Range only involves the endpoints of the list. The middle term could be ANY number within that range. For example:
{40, 40, 40, 40, 80} -- median = 40
{40, 50, 60, 70, 80} -- median = 60
{40, 80, 80, 80, 80} -- median = 80

Likewise, a range of 50 to 90 could give you any of the following for class B(rown):
{50, 50, 50, 50, 90} -- median = 50
{50, 51, 62, 84, 90} -- median = 62
{50, 90, 90, 90, 90} -- median = 90

In order for the statement to be sufficient to answer the question, you would have to be say whether all possible medians for all possible set As were always greater than (or always less than) the medians for all possible set Bs. Since we have a "sometimes it might be, sometimes it might not" situation, this statement is INSUFFICIENT.


Statement 2, however, tells you that it's possible to pair up each student so that each score in set A corresponds to a HIGHER score in set B.

So if you listed out the elements in set A in ascending order: { p, q, r, s, t}
then set B must contain:
{#bigger than p, #bigger than q, #bigger than r, #bigger than s, #bigger than t}

What is the median of set A? The middle term-- r. What's the median of set B? Something bigger than r. Even though I have NO IDEA what those numbers are, if I put them in order I know that the middle term of set B will have to be greater than the middle term of set A. SUFFICIENT.


Hope this helps.
General Discussion
User avatar
siddhans
Manager
Manager
Joined: 29 Jan 2011
Posts: 160
Own Kudos [?]: 711 [1]
Given Kudos: 87
Send PM
DS - MGMAT 10 students took a chemistry exam [#permalink] New post   Updated on: 20 Jun 2011, 22:27
1
Bookmarks
Please explain in detail...

10 students took a chemistry exam that was graded on a scale of 0 to 100. Five of the students were in Dr. Adams’ class and the other five students were in Dr. Brown’s class. Is the median score for Dr. Adams’ students greater than the median score for Dr. Brown’s students?

(1) The range of scores for students in Dr. Adams’ class was 40 to 80, while the range of scores for students in Dr. Brown’s class was 50 to 90.

(2) If the students are paired in study teams such that each student from Dr. Adams’ class has a partner from Dr. Brown’s class, there is a way to pair the 10 students such that the higher scorer in each pair is one of Dr. Brown’s students.

Originally posted by siddhans on 20 Jun 2011, 06:27.
Last edited by siddhans on 20 Jun 2011, 22:27, edited 1 time in total.
User avatar
kp1811
Manager
Manager
Joined: 30 Aug 2009
Posts: 132
Own Kudos [?]: 355 [3]
Given Kudos: 5
Location: India
Concentration: General Management
Send PM
Re: MGMAT DS [#permalink] New post   20 Jun 2011, 06:40
3
Kudos
siddhans wrote:
Please explain in detail...

10 students took a chemistry exam that was graded on a scale of 0 to 100. Five of the students were in Dr. Adams’ class and the other five students were in Dr. Brown’s class. Is the median score for Dr. Adams’ students greater than the median score for Dr. Brown’s students?

(1) The range of scores for students in Dr. Adams’ class was 40 to 80, while the range of scores for students in Dr. Brown’s class was 50 to 90.

(2) If the students are paired in study teams such that each student from Dr. Adams’ class has a partner from Dr. Brown’s class, there is a way to pair the 10 students such that the higher scorer in each pair is one of Dr. Brown’s students.


Statement1 -
Given
Dr. Adams’ class Range is 40-80
Dr. Brown’s class Range is 50 to 90

Case 1
Scores in Dr. Adams’ class can be 40,50,75,80,80 so median is 75
Scores in Dr. Brown’s class can be 50,60,70,80,90 so median is 70

and the answer is Yes

Case 2
Scores in Dr. Adams’ class can be 40,50,75,80,80 so median is 75
Scores in Dr. Brown’s class can be 50,60,80,85,90 so median is 80

and the answer is No

Hence Insuff

Statement 2
What can be concluded that all students of Dr Brown's Class have scores higher than all the students of Dr Adam's Class. So Median of Dr Adam' Class is less than Median of Dr Brown's Class. So we get a definite answer as No. Hence suff

Ans B
User avatar
B
AmritaSarkar89
Manager
Manager
Joined: 22 Feb 2016
Posts: 67
Own Kudos [?]: 52 [1]
Given Kudos: 208
Location: India
Concentration: Economics, Healthcare
Schools: ISB '18 Kellogg '19 (I) Yale '19 (S) Tuck '19 (S)
GMAT 1: 690 Q42 V47
GMAT 2: 710 Q47 V39
GPA: 3.57
Send PM
Re: 10 students took a chemistry exam that was graded on a scale [#permalink] New post   15 Nov 2016, 10:10
1
Kudos
parker wrote:
This is a Yes/No Data Sufficiency question that never requires you to identify the specific values of the medians-- just to answer a question about their relative values.

Remember that the median--as opposed to the mean--only depends on the value of the middle term (or 2 middle terms if you have an even number of elements in your list, but each class has an odd number of students here) when all the terms are listed in order. For example:

For the set {1, 1, 1, 2, 100} -- median = 1
For the set {1, 1, 1, 1, 1} -- median = 1
For the set {-1000, -100, 1, 20, 99999}-- yup, median still equals 1.

Statement 1 tells you about the RANGE of scores in class A(dams). Range only involves the endpoints of the list. The middle term could be ANY number within that range. For example:
{40, 40, 40, 40, 80} -- median = 40
{40, 50, 60, 70, 80} -- median = 60
{40, 80, 80, 80, 80} -- median = 80

Likewise, a range of 50 to 90 could give you any of the following for class B(rown):
{50, 50, 50, 50, 90} -- median = 50
{50, 51, 62, 84, 90} -- median = 62
{50, 90, 90, 90, 90} -- median = 90

In order for the statement to be sufficient to answer the question, you would have to be say whether all possible medians for all possible set As were always greater than (or always less than) the medians for all possible set Bs. Since we have a "sometimes it might be, sometimes it might not" situation, this statement is INSUFFICIENT.


Statement 2, however, tells you that it's possible to pair up each student so that each score in set A corresponds to a HIGHER score in set B.

So if you listed out the elements in set A in ascending order: { p, q, r, s, t}
then set B must contain:
{#bigger than p, #bigger than q, #bigger than r, #bigger than s, #bigger than t}

What is the median of set A? The middle term-- r. What's the median of set B? Something bigger than r. Even though I have NO IDEA what those numbers are, if I put them in order I know that the middle term of set B will have to be greater than the middle term of set A. SUFFICIENT.


Hope this helps.


I remember totally freaking out when this question appeared in my Mock and I thought whoa I am so bad and I will never get it correct. but careful examination of of the question stem and playing with variables helped me get the correct answer. Now looking at your explanation boosted me further as I had moved in the exact way. YAY! Thanks these little victories means a lot in this painful journey.
User avatar
S
Nunuboy1994
Director
Director
Joined: 12 Nov 2016
Posts: 569
Own Kudos [?]: 118 [0]
Given Kudos: 167
Location: United States
Schools: Yale '18
GMAT 1: 650 Q43 V37
GRE 1: Q157 V158
GPA: 2.66
Send PM
Re: 10 students took a chemistry exam that was graded on a scale [#permalink] New post   10 Sep 2017, 23:39
ace001 wrote:
10 students took a chemistry exam that was graded on a scale of 0 to 100. Five of the students were in Dr. Adams’ class and the other five students were in Dr. Brown’s class. Is the median score for Dr. Adams’ students greater than the median score for Dr. Brown’s students?

(1) The range of scores for students in Dr. Adams’ class was 40 to 80, while the range of scores for students in Dr. Brown’s class was 50 to 90.

(2) If the students are paired in study teams such that each student from Dr. Adams’ class has a partner from Dr. Brown’s class, there is a way to pair the 10 students such that the higher scorer in each pair is one of Dr. Brown’s students.


Nice question

All statement 2 is basically saying is that for every student in Dr. Adams class, a student in Dr. Browns class scored higher- so if both classes have the same number of people then the median will naturally be higher even if you minimize the potential scores of Dr. Browns class

Dr A. [10,20,30,40,50]

Dr B [20,30,40,50,60]

The median is clearly higher

B
User avatar
G
Madhavi1990
Senior Manager
Senior Manager
Joined: 15 Jan 2017
Posts: 259
Own Kudos [?]: 85 [0]
Given Kudos: 932
Send PM
Re: 10 students took a chemistry exam that was graded on a scale [#permalink] New post   13 Sep 2017, 00:39
Pretty much a dead giveway with B :)
for A) we don't know the exact scores so Median can be higher for either Dr A or Dr B
B) says each time the score for Dr B is higher --> therefore Me is higher
User avatar
S
tinytiger
Manager
Manager
Joined: 26 Aug 2017
Posts: 50
Own Kudos [?]: 107 [0]
Given Kudos: 696
Location: Singapore
Schools: INSEAD Sept'21 Intake (A$) Wharton '23 (II)
GMAT 1: 710 Q49 V37
GMAT 2: 760 Q50 V44
WE:General Management (Health Care)
Send PM
GMAT ToolKit User Reviews Badge
Re: 10 students took a chemistry exam that was graded on a scale [#permalink] New post   02 Aug 2019, 02:13
Another way to make this question less of a giveaway and with slightly more difficulty would be to have 2 pairs (out of the 5) of students where Brown's student scores lower than the other student; we would then need to determine further if the medians actually differ enough.

E.g. student pairing (Adam on top, Brown below as arranged), with scoring from 1-10:
1 2 3 4 5
2 1 2 5 6 ---->>> (Median, Adam) = 3 > 2 (Median, Brown)

vs

1 2 3 4 5
4 3 1 3 6 ---->>> (Median, Adam) = 3 NOT > 3 (Median, Brown)
User avatar
B
Wai22
Intern
Intern
Joined: 03 May 2022
Posts: 12
Own Kudos [?]: 5 [0]
Given Kudos: 58
Location: India
Schools: HEC Essec "25
GPA: 3.23
Send PM
Re: 10 students took a chemistry exam that was graded on a scale [#permalink] New post   04 Nov 2022, 00:12
parker wrote:
This is a Yes/No Data Sufficiency question that never requires you to identify the specific values of the medians-- just to answer a question about their relative values.

Remember that the median--as opposed to the mean--only depends on the value of the middle term (or 2 middle terms if you have an even number of elements in your list, but each class has an odd number of students here) when all the terms are listed in order. For example:

For the set {1, 1, 1, 2, 100} -- median = 1
For the set {1, 1, 1, 1, 1} -- median = 1
For the set {-1000, -100, 1, 20, 99999}-- yup, median still equals 1.

Statement 1 tells you about the RANGE of scores in class A(dams). Range only involves the endpoints of the list. The middle term could be ANY number within that range. For example:
{40, 40, 40, 40, 80} -- median = 40
{40, 50, 60, 70, 80} -- median = 60
{40, 80, 80, 80, 80} -- median = 80

Likewise, a range of 50 to 90 could give you any of the following for class B(rown):
{50, 50, 50, 50, 90} -- median = 50
{50, 51, 62, 84, 90} -- median = 62
{50, 90, 90, 90, 90} -- median = 90

In order for the statement to be sufficient to answer the question, you would have to be say whether all possible medians for all possible set As were always greater than (or always less than) the medians for all possible set Bs. Since we have a "sometimes it might be, sometimes it might not" situation, this statement is INSUFFICIENT.


Statement 2, however, tells you that it's possible to pair up each student so that each score in set A corresponds to a HIGHER score in set B.

So if you listed out the elements in set A in ascending order: { p, q, r, s, t}
then set B must contain:
{#bigger than p, #bigger than q, #bigger than r, #bigger than s, #bigger than t}

What is the median of set A? The middle term-- r. What's the median of set B? Something bigger than r. Even though I have NO IDEA what those numbers are, if I put them in order I know that the middle term of set B will have to be greater than the middle term of set A. SUFFICIENT.


Hope this helps.


Wouldn't the phrase "there is a way to pair" imply the fact that there are possible ways in which we could pair these 10 students such that some Dr.A students might have scored higher than Dr.B's and some might have not.... hence proving the statement to be insufficient??

This really threw me off during my mock :(
User avatar
B
Wai22
Intern
Intern
Joined: 03 May 2022
Posts: 12
Own Kudos [?]: 5 [0]
Given Kudos: 58
Location: India
Schools: HEC Essec "25
GPA: 3.23
Send PM
10 students took a chemistry exam that was graded on a scale [#permalink] New post   07 Nov 2022, 03:21
kapil1995 wrote:
Wai22 wrote:
parker wrote:
This is a Yes/No Data Sufficiency question that never requires you to identify the specific values of the medians-- just to answer a question about their relative values.

Remember that the median--as opposed to the mean--only depends on the value of the middle term (or 2 middle terms if you have an even number of elements in your list, but each class has an odd number of students here) when all the terms are listed in order. For example:

For the set {1, 1, 1, 2, 100} -- median = 1
For the set {1, 1, 1, 1, 1} -- median = 1
For the set {-1000, -100, 1, 20, 99999}-- yup, median still equals 1.

Statement 1 tells you about the RANGE of scores in class A(dams). Range only involves the endpoints of the list. The middle term could be ANY number within that range. For example:
{40, 40, 40, 40, 80} -- median = 40
{40, 50, 60, 70, 80} -- median = 60
{40, 80, 80, 80, 80} -- median = 80

Likewise, a range of 50 to 90 could give you any of the following for class B(rown):
{50, 50, 50, 50, 90} -- median = 50
{50, 51, 62, 84, 90} -- median = 62
{50, 90, 90, 90, 90} -- median = 90

In order for the statement to be sufficient to answer the question, you would have to be say whether all possible medians for all possible set As were always greater than (or always less than) the medians for all possible set Bs. Since we have a "sometimes it might be, sometimes it might not" situation, this statement is INSUFFICIENT.


Statement 2, however, tells you that it's possible to pair up each student so that each score in set A corresponds to a HIGHER score in set B.

So if you listed out the elements in set A in ascending order: { p, q, r, s, t}
then set B must contain:
{#bigger than p, #bigger than q, #bigger than r, #bigger than s, #bigger than t}

What is the median of set A? The middle term-- r. What's the median of set B? Something bigger than r. Even though I have NO IDEA what those numbers are, if I put them in order I know that the middle term of set B will have to be greater than the middle term of set A. SUFFICIENT.


Hope this helps.


Wouldn't the phrase "there is a way to pair" imply the fact that there are possible ways in which we could pair these 10 students such that some Dr.A students might have scored higher than Dr.B's and some might have not.... hence proving the statement to be insufficient??

This really threw me off during my mock :(


As per given condition in statement 2 ,we can have 15 pairs .

Out of 15 pairs ,10 pairs have students with Brown's students with higher score.

So,It clearly gives most pairs have Brown's students with higher score.

It is only possible when atleast 1 Brown's students score more than Adams students

So, ultimately median of Brown's students will be more

Answer B

Posted from my mobile device


I'm unable to understand how we deduced the number of pairs to be 15....
since the condition given in Statement 2 reads "If the students are paired in study teams such that each student from Dr. Adams’ class has a partner from Dr. Brown’s class.." which would imply that we have a total of 25 WAYS from which we could choose a total of 5 pairs (10 students)....

Furthermore the prompt also states that "there is a way to pair these 10 students" - referring to the 10 students rather than to the number of pairs....
User avatar
B
Apeksha2101
Intern
Intern
Joined: 31 May 2018
Posts: 17
Own Kudos [?]: [0]
Given Kudos: 17
Send PM
10 students took a chemistry exam that was graded on a scale [#permalink] New post   01 Apr 2024, 01:46
parker wrote:
This is a Yes/No Data Sufficiency question that never requires you to identify the specific values of the medians-- just to answer a question about their relative values.

Remember that the median--as opposed to the mean--only depends on the value of the middle term (or 2 middle terms if you have an even number of elements in your list, but each class has an odd number of students here) when all the terms are listed in order. For example:

For the set {1, 1, 1, 2, 100} -- median = 1
For the set {1, 1, 1, 1, 1} -- median = 1
For the set {-1000, -100, 1, 20, 99999}-- yup, median still equals 1.

Statement 1 tells you about the RANGE of scores in class A(dams). Range only involves the endpoints of the list. The middle term could be ANY number within that range. For example:
{40, 40, 40, 40, 80} -- median = 40
{40, 50, 60, 70, 80} -- median = 60
{40, 80, 80, 80, 80} -- median = 80

Likewise, a range of 50 to 90 could give you any of the following for class B(rown):
{50, 50, 50, 50, 90} -- median = 50
{50, 51, 62, 84, 90} -- median = 62
{50, 90, 90, 90, 90} -- median = 90

In order for the statement to be sufficient to answer the question, you would have to be say whether all possible medians for all possible set As were always greater than (or always less than) the medians for all possible set Bs. Since we have a "sometimes it might be, sometimes it might not" situation, this statement is INSUFFICIENT.


Statement 2, however, tells you that it's possible to pair up each student so that each score in set A corresponds to a HIGHER score in set B.

So if you listed out the elements in set A in ascending order: { p, q, r, s, t}
then set B must contain:
{#bigger than p, #bigger than q, #bigger than r, #bigger than s, #bigger than t}

What is the median of set A? The middle term-- r. What's the median of set B? Something bigger than r. Even though I have NO IDEA what those numbers are, if I put them in order I know that the middle term of set B will have to be greater than the middle term of set A. SUFFICIENT.


Hope this helps.





 

­But where in question it is mentioned that it needs to be done in corresponding way?
In that case if we have sets like:
Set A { 40, 40, 80, 80, 80}  => median = 80
Set B {50, 50, 50, 90, 90} => median = 50

And if we pair {40-50} then it also insuffient.­
GMAT Club Bot
gmatclubot
10 students took a chemistry exam that was graded on a scale [#permalink]
01 Apr 2024, 01:46
Moderator:
Bunuel
Math Expert
92915 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions