Last visit was: 09 Oct 2024, 21:46 It is currently 09 Oct 2024, 21:46
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
SORT BY:
Date
Tags:
Difficulty: 555-605 Level,   Overlapping Sets,                     
Show Tags
Hide Tags
User avatar
Joined: 24 Aug 2009
Posts: 127
Own Kudos [?]: 350 [141]
Given Kudos: 46
Send PM
Most Helpful Reply
Math Expert
Joined: 02 Sep 2009
Posts: 96014
Own Kudos [?]: 666804 [22]
Given Kudos: 87567
Send PM
avatar
Joined: 16 Dec 2013
Posts: 22
Own Kudos [?]: 40 [22]
Given Kudos: 31
Location: United States
Schools: Ross '17 (M)
GMAT 1: 660 Q42 V40
GMAT 2: 710 Q47 V42
WE:Military Officer (Military & Defense)
Send PM
General Discussion
User avatar
Joined: 29 Jul 2009
Posts: 108
Own Kudos [?]: 155 [4]
Given Kudos: 6
Send PM
Re: OG 12th edition - DS [#permalink]
2
Kudos
1
Bookmarks
Is the answer D, either statement is sufficient?

Given
Total students who who study S or F or both=300
Those who study S=200

(1) Of the 300 students, 60 do not study Spanish.
Those who study F = 300-60=240

240+200=440 students in F and S classes

Since only 300 students are in the school, the overlap is 440-300=140, who study both

====>sufficient

(2) A total of 240 of the students study Spanish.

240+200=440 students in F and S classes

Since only 300 students are in the school, the overlap is 440-300=140, who study both


====>sufficient
avatar
Joined: 13 Feb 2012
Posts: 11
Own Kudos [?]: 123 [0]
Given Kudos: 14
WE:Other (Transportation)
Send PM
Re: In Jefferson School, 300 students study French or Spanish or [#permalink]
I do not understand how we assume that Jefferson School has only 300 students. If this is not the total number then we cannot say anything from the statements, so answer is E. Am I right??
avatar
Joined: 13 Feb 2012
Posts: 11
Own Kudos [?]: 123 [0]
Given Kudos: 14
WE:Other (Transportation)
Send PM
Re: In Jefferson School, 300 students study French or Spanish or [#permalink]
Bunuel
tom09b
I do not understand how we assume that Jefferson School has only 300 students. If this is not the total number then we cannot say anything from the statements, so answer is E. Am I right??

We are not assuming that. We are told that "in Jefferson School, 300 students study French or Spanish or both", there might be more students who study neither French nor Spanish. But this piece of information tells us that among these 300 students there is none who study neither French nor Spanish. So, 300={French}+{Spanish}-{Both}.

In Jefferson School, 300 students study French or Spanish or both. If 100 of these students do not study French, how many of these students study both French and Spanish?

Given: 300={French}+{Spanish}-{Both} and {Spanish}-{Both}=100 --> 300={French}+100 --> {French}=200.
Question: {Both}=?

(1) Of the 300 students, 60 do not study Spanish --> {French}-{Both}=60 --> 200-{Both}=60 --> {Both}=140. Sufficient.

(2) A total of 240 of the students study Spanish --> {Spanish}=240 --> 240-{Both}=100 ---> {Both}=140. Sufficient.

Answer: D.

I should have paid more attention to If 100 of these students. Thanks again!
User avatar
Joined: 27 Jul 2011
Posts: 118
Own Kudos [?]: 1054 [12]
Given Kudos: 103
Send PM
Re: In Jefferson School, 300 students study French or Spanish or [#permalink]
11
Kudos
1
Bookmarks
Please check the attachment for matrix approach ...which is actually easier than than the set approach

First one is for option A and second one is for option B

NS n NF = 0 as stated all of them either take Spanish of French
Attachments

matrix.png
matrix.png [ 8.79 KiB | Viewed 54440 times ]

avatar
Joined: 09 Sep 2013
Posts: 3
Own Kudos [?]: 12 [7]
Given Kudos: 5
Location: United States
Concentration: General Management, Entrepreneurship
WE:General Management (Real Estate)
Send PM
Re: In Jefferson School, 300 students study French or Spanish or [#permalink]
6
Kudos
1
Bookmarks
If you are making the matrix, you have to realize that No Spanish and No French = 0. That's the tricky part about the matrix.
avatar
Joined: 26 May 2013
Posts: 28
Own Kudos [?]: 95 [17]
Given Kudos: 10
Location: United States
Surendra: Cherukuri
Concentration: Operations, Technology
GMAT 1: 670 Q48 V34
GMAT 2: 720 Q50 V36
GPA: 4
WE:Research (Telecommunications)
Send PM
Re: In Jefferson School, 300 students study French or Spanish or [#permalink]
16
Kudos
ISBtarget
In Jefferson School, 300 students study French or Spanish or both. If 100 of these students do not study French, how many of these students study both French and Spanish?

(1) Of the 300 students, 60 do not study Spanish.
(2) A total of 240 of the students study Spanish.

The answer is D.
Its easy to solve with venn diagram approach
Attachments

File comment: Now
F= total number of students studying french =F
S= total number of students studying Spanish =S
F' = Students studying only french
S'=Students studying only spanish
F & S = students studying both french and spanish
Now we need to find out F & S
We have F + S =300 (whether french or spanish or both)
S' =100 (Students who study spanish but not french)
1.Of the 300 students, 60 do not study Spanish
this 60 = F'( students who study only french but not spanish)
so now looking at diagram F'+S'+ F&S = F+S =300
substituting 100+60+ F&S =300
F&S =140
2. A total of 240 of the students study Spanish
i.e. S'+ F&S =240 (total who study spanish)
we know S' =100
so F&S =140.
Give me KUDOS if this helps

Untitled.png
Untitled.png [ 10.01 KiB | Viewed 50805 times ]

User avatar
Joined: 17 May 2012
Posts: 25
Own Kudos [?]: 53 [0]
Given Kudos: 126
Send PM
In Jefferson School, 300 students study French or Spanish or [#permalink]
Hi Bunuel,

It might seem as a stupid question and I will request you to bare with me. I seem to understand how you get this part
Quote:
Given: 300={French}+{Spanish}-{Both}

But how do you infer this
Quote:
{Spanish}-{Both}=100
and this
Quote:
{French}-{Both}=60
is beyond me. Shouldn't {French}-{Both} = 240? I don't know what I am missing; I really like the equation approach but I am missing a vital link to form the quoted equations. Thanks a million if you can help on this.
Math Expert
Joined: 02 Sep 2009
Posts: 96014
Own Kudos [?]: 666804 [1]
Given Kudos: 87567
Send PM
Re: In Jefferson School, 300 students study French or Spanish or [#permalink]
1
Kudos
Expert Reply
aj0809
Hi Bunuel,

It might seem as a stupid question and I will request you to bare with me. I seem to understand how you get this part
Quote:
Given: 300={French}+{Spanish}-{Both}

But how do you infer this
Quote:
{Spanish}-{Both}=100
and this
Quote:
{French}-{Both}=60
is beyond me. Shouldn't {French}-{Both} = 240? I don't know what I am missing; I really like the equation approach but I am missing a vital link to form the quoted equations. Thanks a million if you can help on this.

We are told that 100 of these students do not study French, so 100 students study Spanish only, which is {Spanish} - {Both}.
The same with {French} - {Both} = 60. 60 do not study Spanish, means that 60 students study French only, which is {French} - {Both}.

Theory on Overlapping Sets:
advanced-overlapping-sets-problems-144260.html
how-to-draw-a-venn-diagram-for-problems-98036.html

DS Overlapping Sets Problems to practice: search.php?search_id=tag&tag_id=45
PS Overlapping Sets Problems to practice: search.php?search_id=tag&tag_id=65
User avatar
Joined: 23 Nov 2014
Posts: 19
Own Kudos [?]: 13 [0]
Given Kudos: 22
Location: China
Concentration: Entrepreneurship, General Management
GMAT 1: 550 Q41 V25
GMAT 2: 680 Q47 V35
WE:General Management (Hospitality and Tourism)
Send PM
Re: In Jefferson School, 300 students study French or Spanish or [#permalink]
Bunuel
tom09b
I do not understand how we assume that Jefferson School has only 300 students. If this is not the total number then we cannot say anything from the statements, so answer is E. Am I right??

We are not assuming that. We are told that "in Jefferson School, 300 students study French or Spanish or both", there might be more students who study neither French nor Spanish. But this piece of information tells us that among these 300 students there is none who study neither French nor Spanish. So, 300={French}+{Spanish}-{Both}.

In Jefferson School, 300 students study French or Spanish or both. If 100 of these students do not study French, how many of these students study both French and Spanish?

Given: 300 = {French} + {Spanish} - {Both} and {Spanish} - {Both} = 100 --> 300 = {French} + 100 --> {French} = 200.
Question: {Both}=?

(1) Of the 300 students, 60 do not study Spanish --> {French} - {Both} = 60 --> 200 - {Both} = 60 --> {Both} = 140. Sufficient.

(2) A total of 240 of the students study Spanish --> {Spanish} = 240 --> 240 - {Both} = 100 ---> {Both} = 140. Sufficient.

Answer: D.


Thanks Bunuel. Now its clear.This is an interesting problem because I assumed there would be some students who study neither. But I have learnt a new way to look at these problems and read carefully to understand the exact meaning. :-D :-D :-D :-D :-D :-D :-D

Insanity: doing the same thing over and over again and expecting different results. - Holds True for Learning for GMAT
User avatar
Joined: 17 May 2012
Posts: 25
Own Kudos [?]: 53 [0]
Given Kudos: 126
Send PM
Re: In Jefferson School, 300 students study French or Spanish or [#permalink]
Hi All,

I found the Venn Diagram approach is the best way to solve this Q. For more details check out the below link:
https://www.gmatquantum.com/og13/138-dat ... ition.html

Thanks,
AJ
Joined: 05 Jan 2017
Posts: 410
Own Kudos [?]: 294 [0]
Given Kudos: 15
Location: India
Send PM
Re: In Jefferson School, 300 students study French or Spanish or [#permalink]
Prompt analysis
No. of student learning french = f
No. of students learning spanish = s

Therefore 300 =f +s +f and s and s =100.

Superset
The value of fs will lie in the range of 0 to 200.

Translation
In order to find f and s, we need:
1# the value of f.
2# the exact value of f and s
3# any equation to find f and f and s.

Statement analysis

St 1: f =60. Therefore from the above equation, we can find f and s =140 .ANSWER.
St 2: s +f and s =240. f and s =140. ANSWER.

Option D
Tutor
Joined: 12 Oct 2010
Status:GMATH founder
Posts: 891
Own Kudos [?]: 1469 [1]
Given Kudos: 56
Send PM
Re: In Jefferson School, 300 students study French or Spanish or [#permalink]
1
Kudos
Expert Reply
ISBtarget
In Jefferson School, 300 students study French or Spanish or both. If 100 of these students do not study French, how many of these students study both French and Spanish?

(1) Of the 300 students, 60 do not study Spanish.
(2) A total of 240 of the students study Spanish.

\(? = {\text{French}} \cap {\text{Spanish}} = x\,\,\,\,\left( {{\text{see}}\,\,{\text{image}}\,\,{\text{attached}}} \right)\)

\(\left( 1 \right)\,\,\,300 = 60 + x + 100\,\,\,\,\, \Rightarrow \,\,\,\,x\,\,\,{\text{unique}}\)

\(\left( 2 \right)\,\,\,240 = x + 100\,\,\,\,\, \Rightarrow \,\,\,\,x\,\,\,{\text{unique}}\)

This solution follows the notations and rationale taught in the GMATH method.

Regards,
Fabio.
Attachments

12Set18_4r.gif
12Set18_4r.gif [ 19.03 KiB | Viewed 25511 times ]

Joined: 20 May 2019
Posts: 37
Own Kudos [?]: 82 [0]
Given Kudos: 5
Location: India
GMAT 1: 760 Q51 V41
Send PM
Re: In Jefferson School, 300 students study French or Spanish or [#permalink]
ISBtarget
In Jefferson School, 300 students study French or Spanish or both. If 100 of these students do not study French, how many of these students study both French and Spanish?

(1) Of the 300 students, 60 do not study Spanish.
(2) A total of 240 of the students study Spanish.

Hi ISBtarget

Another good question involving Sets Theory this time.

So let's try to figure this out...

Question stem:

Total students = 300
Students study: French only [F], Spanish only [S] or both[F&S]
Students not studying French = 100 = [S]

Thus, 300 = [F] + [S] + [F&S]
==> 300 = [F] + 100 + [F&S]. {Equation 1}

To find: [F&S]

Statement 1: Of the 300 students, 60 do not study Spanish.
So, [F] = 60
Substituting this in equation 1:
300 = 60 + 100 + [F&S]
Thus, [F&S] = 140

Now, we know answer could be A or D

Statement 2:
A total of 240 of the students study Spanish.
So, [S] + [F&S] = 240
==> 100 + [F&S] = 240
Thus, [F&S] = 140

As both statements are independently able to give us the solution, Answer is (D).

Is my explanation fine? Would anyone here like me to explain anything else?
Pls share your thoughts. Thank you :)
Joined: 11 Aug 2020
Posts: 1232
Own Kudos [?]: 217 [0]
Given Kudos: 332
Send PM
Re: In Jefferson School, 300 students study French or Spanish or [#permalink]
Good question.

In Jefferson School, 300 students study French or Spanish or both. If 100 of these students do not study French, how many of these students study both French and Spanish?

F (only) + S (only) + Both = 300
100 DO NOT study F <--- Implies that S = 100
F + Both = 200
Both = 200 - F <--- If we can figure out F, then we have an answer.

(1) Of the 300 students, 60 do not study Spanish.

Implies that F = 60

Sufficient.

(2) A total of 240 of the students study Spanish.

Implies that Both + Spanish only = 240.
Both + 100 = 240
Both = 140

Sufficient.

Answer is D.
GMAT Club Legend
GMAT Club Legend
Joined: 08 Jul 2010
Status:GMAT/GRE Tutor l Admission Consultant l On-Demand Course creator
Posts: 6059
Own Kudos [?]: 14277 [1]
Given Kudos: 125
Location: India
GMAT: QUANT+DI EXPERT
Schools: IIM (A) ISB '24
GMAT 1: 750 Q51 V41
WE:Education (Education)
Send PM
Re: In Jefferson School, 300 students study French or Spanish or [#permalink]
1
Bookmarks
Expert Reply
ISBtarget
In Jefferson School, 300 students study French or Spanish or both. If 100 of these students do not study French, how many of these students study both French and Spanish?

(1) Of the 300 students, 60 do not study Spanish.
(2) A total of 240 of the students study Spanish.

Answer: Option D

Video solution by GMATinsight



Get TOPICWISE: Concept Videos | Practice Qns 100+ | Official Qns 50+ | 100% Video solution CLICK HERE.

Two MUST join YouTube channels for GMAT aspirant GMATinsight (1000+ FREE Videos) and GMATclub :)
For a Comprehensive Topicwise Quant Video course at an affordable price CLICK HERE
Joined: 31 Mar 2022
Posts: 11
Own Kudos [?]: 2 [0]
Given Kudos: 26
Location: India
Concentration: General Management, Entrepreneurship
GPA: 3.4
Send PM
Re: In Jefferson School, 300 students study French or Spanish or [#permalink]
ISBtarget
In Jefferson School, 300 students study French or Spanish or both. If 100 of these students do not study French, how many of these students study both French and Spanish?

(1) Of the 300 students, 60 do not study Spanish.
(2) A total of 240 of the students study Spanish.


While applying statement 2.
It’s given in statement 2 that Spanish has 240 students. That means 240 students would include students that are enrolled only in Spanish(let that be S) as well as students enrolled both in Spanish and French(let that be x) .
=> 240 = S + x
AND we are given in the Question stem that Spanish alone (S) has 200 students.
=> 240-200 = x = 40
Thus, if we subtract Spanish only (S) from Both Spanish and French (x) students , we get 40 and not 140.
Please let me know where am I wrong? :)
Joined: 23 Mar 2021
Status:Trying to push it higher!
Posts: 57
Own Kudos [?]: 61 [0]
Given Kudos: 748
Location: India
Concentration: Strategy, General Management
GPA: 3.5
WE:Analyst (Computer Software)
Send PM
Re: In Jefferson School, 300 students study French or Spanish or [#permalink]
parthadlakha
ISBtarget
In Jefferson School, 300 students study French or Spanish or both. If 100 of these students do not study French, how many of these students study both French and Spanish?

(1) Of the 300 students, 60 do not study Spanish.
(2) A total of 240 of the students study Spanish.


While applying statement 2.
It’s given in statement 2 that Spanish has 240 students. That means 240 students would include students that are enrolled only in Spanish(let that be S) as well as students enrolled both in Spanish and French(let that be x) .
=> 240 = S + x
AND we are given in the Question stem that Spanish alone (S) has 200 students.
=> 240-200 = x = 40
Thus, if we subtract Spanish only (S) from Both Spanish and French (x) students , we get 40 and not 140.
Please let me know where am I wrong? :)

Consider the table below:


Study SpanishDon't Study SpanishTotal
Study French??200 (300 - 100)
Don't Study French?0100
Total240 (from statement 2)60 (300 - 240)300

Note that in statement 1 also, we are given the value of 60 so we can find all other values.



Study SpanishDon't Study SpanishTotal
Study French?200 - ?200
Don't Study French100 - ?0100
Total24060300


So,
From statement 1, we can infer that 60 students study French only. Therefore, 140 students study both languages. So, the number of students who study both French and Spanish is 140. So, statement 1 is sufficient.

Checking statement 2, we have 240 students study Spanish, from this 100 students don't study French so they are the ones who study only Spanish. Therefore, 140 students study both. Statement 2 is also sufficient.



Study SpanishDon't Study SpanishTotal
Study French14060200
Don't Study French1000100
Total24060300

So option D is correct.
The trick here is to take the value of 0 in the (Don't study French and Don't study Spanish) cell.
I also fell for that trap before.
GMAT Club Bot
Re: In Jefferson School, 300 students study French or Spanish or [#permalink]
 1   2   
Moderator:
Math Expert
96014 posts