NEW HERE? LEARN MORE
closeclose
Last visit was: 23 Apr 2024, 18:03 It is currently 23 Apr 2024, 18:03
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

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

SORT BY:
Date
Kudos
   1   2 
Tags:
Find Similar Topics 
Show Tags
Hide Tags
avatar
B
Varun1193
Intern
Intern
Joined: 14 Jun 2020
Posts: 5
Own Kudos [?]: 1 [0]
Given Kudos: 16
Send PM
Re: Of the students who eat in a certain cafeteria, each student either [#permalink] New post   12 Apr 2021, 02:01
Bunuel 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?

I'd advise to make a table:



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.





What should be kept in mind while choosing the heads of the table.

I made the table as follows after which I lost the question completely.


.............Lima Beans | Brussel Sprouts
Like
.............
Dislike
.............
avatar
B
wishmasterdj
Manager
Manager
Joined: 04 May 2016
Posts: 96
Own Kudos [?]: 29 [0]
Given Kudos: 10
Location: India
Schools: ISB '18 (A)
GMAT 1: 700 Q48 V37
GPA: 3.2
Send PM
Of the students who eat in a certain cafeteria, each student either [#permalink] New post   21 Apr 2021, 08:57
The best representation for this that I have found is a layered representation. Think of each layer as a choice each student has to make (one for Lima Beans and the other for Brussels Sprouts)

................... Like .......... Dislike
Lima Beans...1/3 .............2/3
..................L....DL;;;.....L..........DL
Brussel.....na....na;;;;..4/15.....2/5 [(2/3) * (3/5)]

So if you know either the overall student population, or the population liking/disliking Lima Beans, you can get the answer, which is basically the ratio 4/15 (arrived at by subtracting 2/5 from 2/3)

Why the traditional matrix form is a little difficult to use for this is because, it does not neatly segregate into the 4 distinct segments LB (Like-Dislike) & BS (Like-Dislike). This question instead, makes you break down the decision choice into two 'levels'. That is why the above-mentioned sequential approach makes this question very easy to crack. Think about it and you will know the subtlety of the approach.
User avatar
L
CrackverbalGMAT
GMAT Club Legend
GMAT Club Legend
Joined: 03 Oct 2013
Affiliations: CrackVerbal
Posts: 4946
Own Kudos [?]: 7624 [0]
Given Kudos: 215
Location: India
Send PM
Re: Of the students who eat in a certain cafeteria, each student either [#permalink] New post   06 Sep 2021, 06:11
Top Contributor
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

No of students who dislike lima beans = 2/3 * 120 = 80
Out of this 80 students who dislike lima beans, no of students who dislike brussels sprouts = 3/5 * 80 = 48
That means, 80 - 48 = 32 students are there who like brussels sprouts but dislike lima beans
Hence, statement 1 is sufficient.

(2) 40 of the students like lima beans

2/3 of the students dislike lima beans means that 1/3 of the students like lima beans.

From statement 2, we can say that 1/3 of total students = 40 ==> Total no of students =40*3 = 120 which is same info as Statement 1.
Hence sufficient.

Option D is the answer.

Thanks,
Clifin J Francis
User avatar
B
akt715
Manager
Manager
Joined: 12 May 2021
Posts: 74
Own Kudos [?]: 6 [0]
Given Kudos: 126
Send PM
Re: Of the students who eat in a certain cafeteria, each student either [#permalink] New post   09 Apr 2022, 00:03
we only know about 2/3 of the students , what they like and dislike but we don't know about the rest 1/3 of the students. In 1/3rd students , there could be students who like sprouts only or who like brussels only or who like them both. So as per my understanding none of the options are sufficient
User avatar
S
woohoo921
Director
Director
Joined: 04 Jun 2020
Posts: 552
Own Kudos [?]: 67 [0]
Given Kudos: 626
Send PM
Re: Of the students who eat in a certain cafeteria, each student either [#permalink] New post   16 Nov 2022, 18:12
KarishmaB wrote:
dimitri92 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

Show Spoiler
Attachment:
del5.jpg


"Of the students who eat in a certain cafeteria, ... "
Say T students eat in the cafeteria

"Of these students, 2/3 dislike lima beans"
(2/3)*T dislike Lima

"and of those who dislike lima beans, 3/5 also dislike brussels sprouts"
Of (2/3)T, (3/5) also dislike brussels so (3/5)*(2/3)T = (2/5)T dislike brussels
We don't know about the rest of the (T/3) that how many of them dislike brussels.

"How many of the students like brussels sprouts but dislike lima beans?"
(2/3)T dislike Lima and (2/5)th of these like Brussels (since (3/5)th of these do not like Brussels)
So (4/15)T dislike Lima but like Brussels.

(1) 120 students eat in the cafeteria
This gives us the value of T. We need to find (4/15)T which we can now. Sufficient

(2) 40 of the students like lima beans
(2/3)T dislike Lima so (1/3)T like Lima. If (1/3)T = 40, we get T = 120.
Again, we can now find (4/15)T. Sufficient.

Answer (D)


KarishmaB
For "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." I originally thought that this meant you cannot dislike both and you cannot like both, so I out zeroes in for likes Brussel Sprouts & Lima Beans and zeroes in for dislikes brussels sprouts and dislikes lima beans. Then, I see that these are both options. So, what does "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" mean then? Is it just a long way of saying that there are no other choices besides lima beans and Brussel sprouts?
Thank you for your time.
User avatar
B
temog
Intern
Intern
Joined: 14 Dec 2022
Posts: 8
Own Kudos [?]: 5 [0]
Given Kudos: 14
Send PM
Re: Of the students who eat in a certain cafeteria, each student either [#permalink] New post   01 Oct 2023, 22:29
Could you please inform me where do I see the info on the question source? Trying to avoid Gmat prep materials Bunuel
GMAT Club Bot
gmatclubot
Re: Of the students who eat in a certain cafeteria, each student either [#permalink]
01 Oct 2023, 22:29
   1   2 
Moderator:
Bunuel
Math Expert
92883 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