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.
Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:
You'll get a free, full-length GMAT practice test, our free Foundations of Math eBook and workshop, and access to free lessons on Sentence Correction and Data Sufficiency.
Reading Comprehension has been added to the Target Test Prep Verbal course. With our full Verbal course, including 1,000+ practice verbal questions and 400+ instructor-led videos, you now have access to everything you need to master GMAT Verbal.
67%
(02:05)
correct
33%
(02:33)
wrong
based on 2146
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
Of the students who eat in a certain cafeteria, each student either
[#permalink]
04 Jun 2010, 06:42
54
Kudos
95
Bookmarks
Expert Reply
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.
Affiliations: AB, cum laude, Harvard University (Class of '02)
Posts: 1020
Location: United States (CO)
Age: 42
GMAT 1:770 Q47 V48
GMAT 2:730 Q44 V47
GMAT 3:750 Q50 V42
GMAT 4:730 Q48 V42 (Online)
GRE 1: Q168 V169
GRE 2: Q170 V170
WE:Education (Education)
Re: Of the students who eat in a certain cafeteria, each student either
[#permalink]
Updated on: 15 Sep 2017, 08:41
4
Kudos
3
Bookmarks
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 [ 275.19 KiB | Viewed 87534 times ]
_________________
My name is Brian McElroy, founder of McElroy Tutoring (http://www.mcelroytutoring.com). I'm a 42 year-old Providence, RI native, and I live with my wife, our three daughters, and our two dogs in beautiful Colorado Springs, Colorado. Ever since graduating from Harvard with honors in the spring of 2002, I’ve worked as a private tutor, essay editor, author, and admissions consultant.
I’ve taken the real GMAT 6 times—including the GMAT online—and have scored in the 700s each time, with personal bests of 770/800 composite, Quant 50/51, Verbal 48/51, IR 8 (2 times) and AWA 6 (4 times), with 3 consecutive 99% scores on Verbal. More importantly, however, I’ve coached hundreds of aspiring MBA students to significantly better GMAT scores over the last two decades, including scores as high as 720 (94%), 740 (97%), 760 (99%), 770, 780, and even the elusive perfect 800, with an average score improvement of over 120 points.
I've also scored a verified perfect 340 on the GRE, and 179 (99%) on the LSAT.
Re: Of the students who eat in a certain cafeteria, each student either
[#permalink]
17 Aug 2010, 13:19
2
Kudos
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...
Re: Of the students who eat in a certain cafeteria, each student either
[#permalink]
18 Aug 2010, 03:35
3
Kudos
1
Bookmarks
Expert Reply
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.
Re: Of the students who eat in a certain cafeteria, each student either
[#permalink]
29 Sep 2014, 20:57
1
Kudos
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:
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
Re: Of the students who eat in a certain cafeteria, each student either
[#permalink]
30 Sep 2014, 00:17
1
Bookmarks
Expert Reply
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:
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? _________________
Re: Of the students who eat in a certain cafeteria, each student either
[#permalink]
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.
Re: Of the students who eat in a certain cafeteria, each student either
[#permalink]
22 Nov 2014, 09:00
Expert Reply
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. _________________
Of the students who eat in a certain cafeteria, each student either
[#permalink]
Updated on: 16 Apr 2021, 05:24
9
Kudos
6
Bookmarks
Expert Reply
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:
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.
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.
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:
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:
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:
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.
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
Re: Of the students who eat in a certain cafeteria, each student either
[#permalink]
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?
Re: Of the students who eat in a certain cafeteria, each student either
[#permalink]
23 Apr 2017, 02:32
Expert Reply
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.
Re: Of the students who eat in a certain cafeteria, each student either
[#permalink]
30 Mar 2018, 01:08
I have a question. Why does nobody take into account the ones who like lima beams, do they like the brussels sprouts or not? We do not know that and for me it is a msileading question because if some of the ones who like lia beams also like brussel sprouts then we do not know how many of them do like and how many do not. So the right anwser must be E
Re: Of the students who eat in a certain cafeteria, each student either
[#permalink]
30 Mar 2018, 03:37
Expert Reply
bernardoassensio wrote:
I have a question. Why does nobody take into account the ones who like lima beams, do they like the brussels sprouts or not? We do not know that and for me it is a msileading question because if some of the ones who like lia beams also like brussel sprouts then we do not know how many of them do like and how many do not. So the right anwser must be E
We have table which takes into account all possible cases: 1. Those who likes lima and likes sprouts; 2. Those who likes lima and do NOT like sprouts; 3. Those who do NOT like lima and likes sprouts; 4. Those who do NOT like lima and do NOT like sprouts.
Re: Of the students who eat in a certain cafeteria, each student either
[#permalink]
01 Dec 2018, 01:29
2
Kudos
Expert Reply
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
"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) _________________
Karishma GMAT Instructor at Angles and Arguments https://anglesandarguments.com/
Re: Of the students who eat in a certain cafeteria, each student either
[#permalink]
19 Jan 2019, 08:13
1
Bookmarks
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
This is overlapping sets, since all the students like and dislikes both foods. I drew a table with the givens and then filled in with information from 1) and 2)
Both 1) and 2) give us sufficient information to solve for x, so C It's pretty quick to check the table to make sure everything matches up.
Re: Of the students who eat in a certain cafeteria, each student either
[#permalink]
15 Nov 2020, 14:33
We're told that 2/3 dislike lime beans. Therefore 1/3 like lima beans.
Out of the 2/3 who dislike lima beans, 3/5 also dislike brussels sprouts. This means of this subset of the 2/3 portion, 60% don't like brussels sprouts (we don't need to calculate the exact total)
How many of the students like brussels sprouts but dislike lima beans? To answer this question we need to know either the number of students that like lima beans (1/3 of the school population) or the total number of students (3/3 of the school population).
(1) Directly gives us our answer. SUFFICIENT.
(2) Directly gives us our answer. SUFFICIENT.
Answer is D. _________________
Help me get better -- please critique my responses!
Re: Of the students who eat in a certain cafeteria, each student either
[#permalink]
12 Apr 2021, 01:01
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 .............
Of the students who eat in a certain cafeteria, each student either
[#permalink]
21 Apr 2021, 07:57
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.
gmatclubot
Of the students who eat in a certain cafeteria, each student either [#permalink]
One of the fastest-growing graduate business schools in Southern California, shaping the future by developing leading thinkers who will stand at the forefront of business growth. MBA Landing | School of Business (ucr.edu)