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

It is currently 21 Feb 2019, 14:08

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
Events & Promotions in February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar
  • Online GMAT boot camp for FREE

     February 21, 2019

     February 21, 2019

     10:00 PM PST

     11:00 PM PST

    Kick off your 2019 GMAT prep with a free 7-day boot camp that includes free online lessons, webinars, and a full GMAT course access. Limited for the first 99 registrants! Feb. 21st until the 27th.
  • Free GMAT RC Webinar

     February 23, 2019

     February 23, 2019

     07:00 AM PST

     09:00 AM PST

    Learn reading strategies that can help even non-voracious reader to master GMAT RC. Saturday, February 23rd at 7 AM PT

Of the students who eat in a certain cafeteria, each student either

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

Hide Tags

 
Senior Manager
Senior Manager
User avatar
B
Affiliations: SPG
Joined: 15 Nov 2006
Posts: 299
Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post 03 Jun 2010, 23:29
20
1
93
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

64% (02:03) correct 36% (02:36) wrong based on 2053 sessions

HideShow timer Statistics

Of the students who eat in a certain cafeteria, each student either likes or dislikes lima beans and each student either likes or dislikes brussels sprouts. Of these students, 2/3 dislike lima beans; and of those who dislike lima beans, 3/5 also dislike brussels sprouts. How many of the students like brussels sprouts but dislike lima beans?

(1) 120 students eat in the cafeteria
(2) 40 of the students like lima beans

Attachment:
del5.jpg
del5.jpg [ 23.82 KiB | Viewed 68316 times ]
Most Helpful Expert Reply
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 53063
Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post 04 Jun 2010, 06:42
36
47
dimitri92 wrote:
What is the best approach to tackle questions like these ?


Of the students who eat in a certain cafeteria, each student either likes or dislikes lima beans and each student either likes or dislikes brussels sprouts. Of these students, 2/3 dislike lima beans; and of those who dislike lima beans, 3/5 also dislike brussels sprouts. How many of the students like brussels sprouts but dislike lima beans?

I'd advise to make a table:

Image

Note that:
"2/3 dislike lima beans" means 2/3 of total dislike lima;
"of those who dislike lima beans, 3/5 also dislike brussels sprouts" means of those who dislike lima \(1-\frac{3}{5}=\frac{2}{5}\) like sprout, or \(\frac{2}{3}*\frac{2}{5}=\frac{4}{15}\) of total dislike lima but like sprouts. So to calculate # of students who dislike lima but like sprouts we should now total # of students (t).

(1) 120 students eat in the cafeteria --> \(t=120\) --> \(x=\frac{4}{15}t=32\). Sufficient.

(2) 40 of the students like lima beans --> total students who like lima + total students who dislike lima = total --> \(40+\frac{2}{3}t=t\) --> \(t=120\) --> \(x=\frac{4}{15}t=32\). Sufficient.

Answer: D.


Attachment:
Lima-Sprouts.JPG
Lima-Sprouts.JPG [ 11.66 KiB | Viewed 77248 times ]

_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

General Discussion
Senior Manager
Senior Manager
avatar
Joined: 25 Jun 2009
Posts: 276
Re: Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post 04 Jun 2010, 02:58
3
dimitri92 wrote:
What is the best approach to tackle questions like these ?



The question is basically asking how many dislikes Lima beans but like Sprouts..

Given 2/3 of the entire student poplutation dont like LIMA.. of these 3/5 DONT like sprouts..so 2/5 like sprouts..

1) Given total students = 120 so 2/3 * 120 = 80 who dislikes lima beans out of these 2/5* 50 are the ones who likes sprouts but dislikes beans ... Hence Sufficient

2) 40 Likes beans so in thats means 120 is the total number of students... same logic as 1 -- Hence Sufficient

hope this helps..!
Senior Manager
Senior Manager
User avatar
Joined: 25 Feb 2010
Posts: 341
Re: Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post 17 Aug 2010, 13:19
Bunuel wrote:
dimitri92 wrote:
What is the best approach to tackle questions like these ?


Of the students who eat in a certain cafeteria, each student either likes or dislikes lima beans and each student either likes or dislikes brussels sprouts. Of these students, 2/3 dislike lima beans; and of those who dislike lima beans, 3/5 also dislike brussels sprouts. How many of the students like brussels sprouts but dislike lima beans?

I'd advise to make a table:
Attachment:
Lima-Sprouts.JPG

Note that:
"2/3 dislike lima beans" means 2/3 of total dislike lima;
"of those who dislike lima beans, 3/5 also dislike brussels sprouts" means of those who dislike lima \(1-\frac{3}{5}=\frac{2}{5}\) like sprout, or \(\frac{2}{3}*\frac{2}{5}=\frac{4}{15}\) of total dislike lima but like sprouts. So to calculate # of students who dislike lima but like sprouts we should now total # of students (t).

Answer: D.


I didn't understand this part...
means of those who dislike lima \(1-\frac{3}{5}=\frac{2}{5}\) like sprout, or
_________________

GGG (Gym / GMAT / Girl) -- Be Serious

Its your duty to post OA afterwards; some one must be waiting for that...

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 53063
Re: Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post 18 Aug 2010, 03:35
3
1
onedayill wrote:
Bunuel wrote:
dimitri92 wrote:
What is the best approach to tackle questions like these ?


Of the students who eat in a certain cafeteria, each student either likes or dislikes lima beans and each student either likes or dislikes brussels sprouts. Of these students, 2/3 dislike lima beans; and of those who dislike lima beans, 3/5 also dislike brussels sprouts. How many of the students like brussels sprouts but dislike lima beans?

I'd advise to make a table:
Attachment:
Lima-Sprouts.JPG

Note that:
"2/3 dislike lima beans" means 2/3 of total dislike lima;
"of those who dislike lima beans, 3/5 also dislike brussels sprouts" means of those who dislike lima \(1-\frac{3}{5}=\frac{2}{5}\) like sprout, or \(\frac{2}{3}*\frac{2}{5}=\frac{4}{15}\) of total dislike lima but like sprouts. So to calculate # of students who dislike lima but like sprouts we should now total # of students (t).

Answer: D.


I didn't understand this part...
means of those who dislike lima \(1-\frac{3}{5}=\frac{2}{5}\) like sprout, or


If "of those who dislike lima beans, 3/5 (40%) also dislike brussels sprouts", hence rest of of those who dislike lima beans or 2/5 (60%) must like sprouts. As "2/3 of total dislike lima beans" then 2/3*2/5=4/15 of total dislike lima but like sprouts.

Hope it's clear.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Manager
Manager
User avatar
Joined: 20 Jan 2014
Posts: 142
Location: India
Concentration: Technology, Marketing
GMAT ToolKit User
Re: Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post 29 Sep 2014, 20:57
Bunuel wrote:
dimitri92 wrote:
What is the best approach to tackle questions like these ?


Of the students who eat in a certain cafeteria, each student either likes or dislikes lima beans and each student either likes or dislikes brussels sprouts. Of these students, 2/3 dislike lima beans; and of those who dislike lima beans, 3/5 also dislike brussels sprouts. How many of the students like brussels sprouts but dislike lima beans?

I'd advise to make a table:
Image
Note that:
"2/3 dislike lima beans" means 2/3 of total dislike lima;
"of those who dislike lima beans, 3/5 also dislike brussels sprouts" means of those who dislike lima \(1-\frac{3}{5}=\frac{2}{5}\) like sprout, or \(\frac{2}{3}*\frac{2}{5}=\frac{4}{15}\) of total dislike lima but like sprouts. So to calculate # of students who dislike lima but like sprouts we should now total # of students (t).

(1) 120 students eat in the cafeteria --> \(t=120\) --> \(x=\frac{4}{15}t=32\). Sufficient.

(2) 40 of the students like lima beans --> total students who like lima + total students who dislike lima = total --> \(40+\frac{2}{3}t=t\) --> \(t=120\) --> \(x=\frac{4}{15}t=32\). Sufficient.

Answer: D.


Let Total Student are t.
2/3 t dislike lima bean so 1/3 likes lima bean
Now 3/5 * 2/3 *t dislike sprout = 6/15*t dislike both LB and BS

Now we know that how many dislike and Like LB and that dislike both LB and BS
But we do not know how many like BS.
I struck here and selected E wrongly.

Can you please explain in easy language. I did not get the solution
_________________

Consider +1 Kudos Please :)

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 53063
Re: Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post 30 Sep 2014, 00:17
him1985 wrote:
Bunuel wrote:
dimitri92 wrote:
What is the best approach to tackle questions like these ?


Of the students who eat in a certain cafeteria, each student either likes or dislikes lima beans and each student either likes or dislikes brussels sprouts. Of these students, 2/3 dislike lima beans; and of those who dislike lima beans, 3/5 also dislike brussels sprouts. How many of the students like brussels sprouts but dislike lima beans?

I'd advise to make a table:
Image
Note that:
"2/3 dislike lima beans" means 2/3 of total dislike lima;
"of those who dislike lima beans, 3/5 also dislike brussels sprouts" means of those who dislike lima \(1-\frac{3}{5}=\frac{2}{5}\) like sprout, or \(\frac{2}{3}*\frac{2}{5}=\frac{4}{15}\) of total dislike lima but like sprouts. So to calculate # of students who dislike lima but like sprouts we should now total # of students (t).

(1) 120 students eat in the cafeteria --> \(t=120\) --> \(x=\frac{4}{15}t=32\). Sufficient.

(2) 40 of the students like lima beans --> total students who like lima + total students who dislike lima = total --> \(40+\frac{2}{3}t=t\) --> \(t=120\) --> \(x=\frac{4}{15}t=32\). Sufficient.

Answer: D.


Let Total Student are t.
2/3 t dislike lima bean so 1/3 likes lima bean
Now 3/5 * 2/3 *t dislike sprout = 6/15*t dislike both LB and BS

Now we know that how many dislike and Like LB and that dislike both LB and BS
But we do not know how many like BS.
I struck here and selected E wrongly.

Can you please explain in easy language. I did not get the solution


We need to find how many students like brussels sprouts but dislike lima beans (box in red in my solution). Each statement is sufficient to find this value as shown above. Can you please tell me what is unclear there?
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
avatar
Joined: 03 Jul 2014
Posts: 16
Re: Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post 22 Nov 2014, 08:45
I have a question , this is a subtle concept but i guess very important.

Like in this question , i was left little misled by the work either they like or dislike Limabean , and either they like or dislike Sproat. So i thought Neither will be 0

So when do we need to identify the Neither case . I thought here also there will be no neither case ie neither like limabean and sproat.

But i see all the 4 boxes in matrix are filled .






Bunuel wrote:
dimitri92 wrote:
What is the best approach to tackle questions like these ?


Of the students who eat in a certain cafeteria, each student either likes or dislikes lima beans and each student either likes or dislikes brussels sprouts. Of these students, 2/3 dislike lima beans; and of those who dislike lima beans, 3/5 also dislike brussels sprouts. How many of the students like brussels sprouts but dislike lima beans?

I'd advise to make a table:
Attachment:
Lima-Sprouts.JPG

Note that:
"2/3 dislike lima beans" means 2/3 of total dislike lima;
"of those who dislike lima beans, 3/5 also dislike brussels sprouts" means of those who dislike lima \(1-\frac{3}{5}=\frac{2}{5}\) like sprout, or \(\frac{2}{3}*\frac{2}{5}=\frac{4}{15}\) of total dislike lima but like sprouts. So to calculate # of students who dislike lima but like sprouts we should now total # of students (t).

(1) 120 students eat in the cafeteria --> \(t=120\) --> \(x=\frac{4}{15}t=32\). Sufficient.

(2) 40 of the students like lima beans --> total students who like lima + total students who dislike lima = total --> \(40+\frac{2}{3}t=t\) --> \(t=120\) --> \(x=\frac{4}{15}t=32\). Sufficient.

Answer: D.
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 53063
Re: Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post 22 Nov 2014, 09:00
hanschris5 wrote:
I have a question , this is a subtle concept but i guess very important.

Like in this question , i was left little misled by the work either they like or dislike Limabean , and either they like or dislike Sproat. So i thought Neither will be 0

So when do we need to identify the Neither case . I thought here also there will be no neither case ie neither like limabean and sproat.

But i see all the 4 boxes in matrix are filled .






Bunuel wrote:
dimitri92 wrote:
What is the best approach to tackle questions like these ?


Of the students who eat in a certain cafeteria, each student either likes or dislikes lima beans and each student either likes or dislikes brussels sprouts. Of these students, 2/3 dislike lima beans; and of those who dislike lima beans, 3/5 also dislike brussels sprouts. How many of the students like brussels sprouts but dislike lima beans?

I'd advise to make a table:
Attachment:
Lima-Sprouts.JPG

Note that:
"2/3 dislike lima beans" means 2/3 of total dislike lima;
"of those who dislike lima beans, 3/5 also dislike brussels sprouts" means of those who dislike lima \(1-\frac{3}{5}=\frac{2}{5}\) like sprout, or \(\frac{2}{3}*\frac{2}{5}=\frac{4}{15}\) of total dislike lima but like sprouts. So to calculate # of students who dislike lima but like sprouts we should now total # of students (t).

(1) 120 students eat in the cafeteria --> \(t=120\) --> \(x=\frac{4}{15}t=32\). Sufficient.

(2) 40 of the students like lima beans --> total students who like lima + total students who dislike lima = total --> \(40+\frac{2}{3}t=t\) --> \(t=120\) --> \(x=\frac{4}{15}t=32\). Sufficient.

Answer: D.


Each student either likes or dislikes lima beans, means that there are students who does NOT like lima beans.
Each student either likes or dislikes brussels sprouts, means that there are students who does NO like brussels sprouts.

Thus, there might be students who does NOT like either lima beans or brussels sprouts.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
avatar
Joined: 14 May 2014
Posts: 41
Schools: Broad '18 (WA$)
GMAT 1: 700 Q44 V41
GPA: 3.11
GMAT ToolKit User Reviews Badge
Re: Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post 25 Jul 2015, 02:06
Bunuel wrote:
dimitri92 wrote:
What is the best approach to tackle questions like these ?


Of the students who eat in a certain cafeteria, each student either likes or dislikes lima beans and each student either likes or dislikes brussels sprouts. Of these students, 2/3 dislike lima beans; and of those who dislike lima beans, 3/5 also dislike brussels sprouts. How many of the students like brussels sprouts but dislike lima beans?

I'd advise to make a table:
Attachment:
Lima-Sprouts.JPG

Note that:
"2/3 dislike lima beans" means 2/3 of total dislike lima;
"of those who dislike lima beans, 3/5 also dislike brussels sprouts" means of those who dislike lima \(1-\frac{3}{5}=\frac{2}{5}\) like sprout, or \(\frac{2}{3}*\frac{2}{5}=\frac{4}{15}\) of total dislike lima but like sprouts. So to calculate # of students who dislike lima but like sprouts we should now total # of students (t).

(1) 120 students eat in the cafeteria --> \(t=120\) --> \(x=\frac{4}{15}t=32\). Sufficient.

(2) 40 of the students like lima beans --> total students who like lima + total students who dislike lima = total --> \(40+\frac{2}{3}t=t\) --> \(t=120\) --> \(x=\frac{4}{15}t=32\). Sufficient.

Answer: D.


how can we solve this using formula of set theory.

total= not like lima + not like sprouts - not like both
Intern
Intern
avatar
Joined: 02 Dec 2015
Posts: 1
Re: Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post 05 Dec 2015, 20:05
Bingo, I got it at my first attempt. its D.
One rule: If Answer is D, both statements will never conflict.
So, 2/3 dislikes lima beans; it means 1/3 likes lima beans. The number is then (1/3*120) 40.
And statement 2 provides us same number.
So answer is D even without much calculation.
Kudos...........
Manager
Manager
avatar
B
Joined: 26 Jan 2015
Posts: 76
Re: Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post 09 Dec 2015, 10:32
moinbdusa wrote:
Bingo, I got it at my first attempt. its D.
One rule: If Answer is D, both statements will never conflict.
So, 2/3 dislikes lima beans; it means 1/3 likes lima beans. The number is then (1/3*120) 40.
And statement 2 provides us same number.
So answer is D even without much calculation.
Kudos...........


There are going to be cases where for value questions:
Stmnt 1 gives x=10
Stmnt 2 gives x=20
But still the answer is D.
@Bunuel...please correct me if i am wrong.
_________________

Kudos is the best way to say Thank you! Please give me a kudos if you like my post

Intern
Intern
avatar
Joined: 29 Nov 2015
Posts: 13
Re: Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post 29 Dec 2015, 22:49
Bunuel wrote:
dimitri92 wrote:
What is the best approach to tackle questions like these ?


Of the students who eat in a certain cafeteria, each student either likes or dislikes lima beans and each student either likes or dislikes brussels sprouts. Of these students, 2/3 dislike lima beans; and of those who dislike lima beans, 3/5 also dislike brussels sprouts. How many of the students like brussels sprouts but dislike lima beans?

I'd advise to make a table:
Attachment:
The attachment Lima-Sprouts.JPG is no longer available

Note that:
"2/3 dislike lima beans" means 2/3 of total dislike lima;
"of those who dislike lima beans, 3/5 also dislike brussels sprouts" means of those who dislike lima \(1-\frac{3}{5}=\frac{2}{5}\) like sprout, or \(\frac{2}{3}*\frac{2}{5}=\frac{4}{15}\) of total dislike lima but like sprouts. So to calculate # of students who dislike lima but like sprouts we should now total # of students (t).

(1) 120 students eat in the cafeteria --> \(t=120\) --> \(x=\frac{4}{15}t=32\). Sufficient.

(2) 40 of the students like lima beans --> total students who like lima + total students who dislike lima = total --> \(40+\frac{2}{3}t=t\) --> \(t=120\) --> \(x=\frac{4}{15}t=32\). Sufficient.

Answer: D.


I think drawing a correct table here is key. The table I drew was not wrong but it wasn't right for the question asked. So how to ensure that you make the right table?
Attachments

lima beans.JPG
lima beans.JPG [ 17.25 KiB | Viewed 55264 times ]

Director
Director
User avatar
G
Status: Professional GMAT Tutor
Affiliations: AB, cum laude, Harvard University (Class of '02)
Joined: 10 Jul 2015
Posts: 675
Location: United States (CA)
Age: 39
GMAT 1: 770 Q47 V48
GMAT 2: 730 Q44 V47
GMAT 3: 750 Q50 V42
GRE 1: Q168 V169
WE: Education (Education)
Re: Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post Updated on: 15 Sep 2017, 08:41
3
1
Attached is a visual that should help. Remember that all sums of "X" and "not X" must equal 1, so when the question tells us that 2/3 of students dislike lima beans, it is of course also telling us that 1/3 of students like lima beans.

Likewise, when the question tells us "of those who dislike lima beans, 3/5 also dislike brussels sprouts," it is also telling us that of those who dislike lima beans, 2/5 also like brussels sprouts.

Other than that, getting this question right is mostly a matter of organizing your information well using a matrix. See below.
Attachments

Screen Shot 2017-09-14 at 11.59.34 AM.png
Screen Shot 2017-09-14 at 11.59.34 AM.png [ 275.19 KiB | Viewed 25895 times ]


_________________

Harvard grad and 99% GMAT scorer, offering expert, private GMAT tutoring and coaching worldwide since 2002.

One of the only known humans to have taken the GMAT 5 times and scored in the 700s every time (700, 710, 730, 750, 770), including verified section scores of Q50 / V47, as well as personal bests of 8/8 IR (2 times), 6/6 AWA (4 times), 50/51Q and 48/51V (1 question wrong).

You can download my official test-taker score report (all scores within the last 5 years) directly from the Pearson Vue website: https://tinyurl.com/y7knw7bt Date of Birth: 09 December 1979.

GMAT Action Plan and Free E-Book - McElroy Tutoring

Contact: mcelroy@post.harvard.edu (I do not respond to PMs on GMAT Club.)

...or find me on Reddit: http://www.reddit.com/r/GMATpreparation


Originally posted by mcelroytutoring on 05 Apr 2016, 21:34.
Last edited by mcelroytutoring on 15 Sep 2017, 08:41, edited 8 times in total.
Board of Directors
User avatar
P
Joined: 17 Jul 2014
Posts: 2587
Location: United States (IL)
Concentration: Finance, Economics
GMAT 1: 650 Q49 V30
GPA: 3.92
WE: General Management (Transportation)
GMAT ToolKit User Premium Member Reviews Badge
Re: Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post 09 Apr 2016, 13:53
what is x?

1. x=120 sufficient.
2. x/3=40 sufficient.
Attachments

q1.jpg
q1.jpg [ 19.54 KiB | Viewed 34264 times ]

Intern
Intern
avatar
B
Joined: 16 Jul 2016
Posts: 39
Re: Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post 02 Aug 2016, 16:21
I took the table approach, but I used slightly different values as well as decimals.

If we can find x, we have the answer.
Attachments

GMAT - Sheet1.pdf [15.23 KiB]
Downloaded 126 times

To download please login or register as a user

CEO
CEO
User avatar
D
Joined: 11 Sep 2015
Posts: 3445
Location: Canada
Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post Updated on: 16 Apr 2018, 11:57
4
Top Contributor
OluOdekunle wrote:
Of the students who eat in a certain cafeteria, each student either likes or dislikes lima beans and each student either likes or dislikes Brussels sprouts. Of these students, [2][/3] dislike lima beans; and of those who dislike lima beans, [3][/5] also dislike Brussels sprouts. How many of the students like Brussels sprouts but dislike lima beans?

(1) 120 students eat in the cafeteria
(2) 40 of the students like lima beans


We can use the Double Matrix Method to solve this question. This technique can be used for most questions featuring a population in which each member has two characteristics associated with it.
Here, we have a population of students, and the two characteristics are:
- like Brussels sprouts or dislike Brussels sprouts
- like lima beans or dislike lima beans

So, we can set up our diagram as follows:
Image

Target question: How many of the students like Brussels sprouts but dislike lima beans?
Let's place a STAR in the box representing those students who like Brussels sprouts but dislike lima beans.
Image

Since we don't know the TOTAL NUMBER of students, let's let x represent the total student population. So, we'll add that to our diagram as well.
Image

Given: 2/3 dislike lima beans
So, (2/3)x = total number of students who dislike lima beans
This means the other 1/3 LIKE lima beans. In other words, (1/3)x = total number of students who LIKE lima beans.
We'll add that to the diagram:
Image

Given: Of those who dislike lima beans, 3/5 also dislike Brussels sprouts
If (2/3)x = total number of students who dislike lima beans, then (3/5)(2/3)x = total number of students who dislike lima beans AND dislike Brussels sprouts.
(3/5)(2/3)x simplifies to (2/5)x, so we'll add that to our diagram:
Image

Finally, since the two boxes in the right-hand column must add to (2/3)x, we know that the top-right box must = (4/15)x [since (2/3)x - (2/5)x = (4/15)x]
So, we can add that to the diagram:
Image

Great! We're now ready to examine the statements.

Statement 1: 120 students eat in the cafeteria
In other words, x = 120
Plug x = 120 into the top-right box to get: (4/15)(120) = 32
So, there are 32 students who like Brussels sprouts but dislike lima beans.
Image
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: 40 of the students like lima beans.
The left-hand column represents students who like lima beans.
In total, (1/3)x = total number of students who LIKE lima beans.
So, statement 2 is telling us that (1/3)x = 40
We can solve the equation to conclude that x = 120
Once we know the value of x, we can determine the number of students who like Brussels sprouts but dislike lima beans (we already did so in statement 1)
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer =

RELATED VIDEO


MORE PRACTICE

_________________

Test confidently with gmatprepnow.com
Image


Originally posted by GMATPrepNow on 25 Aug 2016, 05:51.
Last edited by GMATPrepNow on 16 Apr 2018, 11:57, edited 1 time in total.
Current Student
avatar
G
Joined: 19 Aug 2016
Posts: 149
Location: India
GMAT 1: 640 Q47 V31
GPA: 3.82
Reviews Badge
Re: Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post 22 Apr 2017, 14:50
@[quote="Bunuel"]
"of those who dislike lima beans, 3/5 also dislike brussels sprouts" means of those who dislike lima \(1-\frac{3}{5}=\frac{2}{5}\) like sprout, or \(\frac{2}{3}*\frac{2}{5}=\frac{4}{15}\) of total dislike lima but like sprouts. So to calculate # of students who dislike lima but like sprouts we should now total # of students (t).

Hi Bunuel,

Can you please elaborate this part? I particularly did not understand the 2/3*2/5 part? Why are we doing this?
_________________

Consider giving me Kudos if you find my posts useful, challenging and helpful!

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 53063
Re: Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post 23 Apr 2017, 02:32
ashikaverma13 wrote:
@
Bunuel wrote:
"of those who dislike lima beans, 3/5 also dislike brussels sprouts" means of those who dislike lima \(1-\frac{3}{5}=\frac{2}{5}\) like sprout, or \(\frac{2}{3}*\frac{2}{5}=\frac{4}{15}\) of total dislike lima but like sprouts. So to calculate # of students who dislike lima but like sprouts we should now total # of students (t).

Hi Bunuel,

Can you please elaborate this part? I particularly did not understand the 2/3*2/5 part? Why are we doing this?


If "of those who dislike lima beans, 3/5 (40%) also dislike brussels sprouts", hence rest of of those who dislike lima beans or 2/5 (60%) must like sprouts. As "2/3 of total dislike lima beans" then 2/3*2/5=4/15 of total dislike lima but like sprouts.

Hope it's clear.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
avatar
B
Joined: 10 Jul 2017
Posts: 1
Re: Of the students who eat in a certain cafeteria, each student either  [#permalink]

Show Tags

New post 18 Feb 2018, 02:01
The key thing to remember that each student either likes or dislikes lima beans and the same applies for brussels sprouts.

So if we have ⅔ of the total who dislike LB and ⅗ of whom also dislike BS.
This means that another portion of people (⅖) who dislike LB like BS. That is what basically is required to know. If we can find the total amount of people then we can solve the problem.
Attachments

Image.png
Image.png [ 33.37 KiB | Viewed 17039 times ]

GMAT Club Bot
Re: Of the students who eat in a certain cafeteria, each student either   [#permalink] 18 Feb 2018, 02:01

Go to page    1   2    Next  [ 29 posts ] 

Display posts from previous: Sort by

Of the students who eat in a certain cafeteria, each student either

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


Copyright

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®.