Last visit was: 20 May 2025, 11:59 It is currently 20 May 2025, 11:59
Home
GMAT
MBA Fair
Messages
Tests
Schools
Events
Rewards
Chat
My Profile
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
Back to Forum
Create Topic
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 20 May 2025
Posts: 101,570
Own Kudos:
725,790
 [36]
Given Kudos: 93,572
Products:
GMAT Club Tests Forum Quiz
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 101,570
Kudos: 725,790
 [36]
Students in certain group know either English or French or both. If 20 06 Nov 2019, 06:16
1
Kudos
Add Kudos
34
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
B
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

75% (hard)

Question Stats:

63% (03:07) correct 37% (03:10) wrong based on 320 sessions

History

Date
Time
Result
Not Attempted Yet
Students in certain group know either English or French or both. If 20% of those who know English do not know French, and 60% of those who know French know English, what part of the entire group knows both languages?

A. 1/2
B. 12/23
C. 23/35
D. 13/27
E. 1/5

Are You Up For the Challenge: 700 Level Questions
ShowHide Answer
Official Answer
B
Most Helpful Reply
User avatar
nick1816
User avatar
Retired Moderator
Joined: 19 Oct 2018
Last visit: 20 May 2025
Posts: 1,853
Own Kudos:
7,644
 [5]
Given Kudos: 707
Location: India
Posts: 1,853
Kudos: 7,644
 [5]
Students in certain group know either English or French or both. If 20 06 Nov 2019, 08:25
2
Kudos
Add Kudos
3
Bookmarks
Bookmark this Post
80% of students who know english = 60% of students who know french

4E=3F
F= \(\frac{4E}{3}\)


part of the entire group knows both languages= \(\frac{0.8E}{E+F-0.8E}\)=\(\frac{12}{23}\)


Bunuel
Students in certain group know either English or French or both. If 20% of those who know English do not know French, and 60% of those who know French know English, what part of the entire group knows both languages?

A. 1/2
B. 12/23
C. 23/35
D. 13/27
E. 1/5

Are You Up For the Challenge: 700 Level Questions
General Discussion
avatar
shashishjha81
avatar
Joined: 22 Aug 2019
Last visit: 30 Mar 2022
Posts: 1
Own Kudos:
2
 [2]
Given Kudos: 1
Posts: 1
Kudos: 2
 [2]
Students in certain group know either English or French or both. If 20 07 Nov 2019, 08:31
1
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
IMO
Answer:3/5
E+F=100;
A+B=E;
B+C=F
A=20,
B=60,
C=20,

SO
60/100
User avatar
ScottTargetTestPrep
User avatar
Target Test Prep Representative
Joined: 14 Oct 2015
Last visit: 20 May 2025
Posts: 20,795
Own Kudos:
25,868
 [3]
Given Kudos: 292
Status:Founder & CEO
Affiliations: Target Test Prep
Location: United States (CA)
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 20,795
Kudos: 25,868
 [3]
Students in certain group know either English or French or both. If 20 12 Nov 2019, 20:24
2
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Bunuel
Students in certain group know either English or French or both. If 20% of those who know English do not know French, and 60% of those who know French know English, what part of the entire group knows both languages?

A. 1/2
B. 12/23
C. 23/35
D. 13/27
E. 1/5

Are You Up For the Challenge: 700 Level Questions

If we let E = the number of students who know English and F = the number of students who know French, we have 0.8E students who know English know French and 0.6F students who know French know English. Since both 0.8E and 0.6F represent the same group of students (i.e., the students who know both languages), they must be equal:

0.8E = 0.6F

8E = 6F

E = 6F/8 = 3F/4

Thus, the fraction of the students who know both languages is:

(0.6F)/(E + F - 0.6F) = (0.6F)/(E + 0.4F) = (3F/5)/(3F/4 + 2F/5) = (3/5)/(3/4 + 2/5) = 12/(15 + 8) = 12/23

Answer: B
avatar
geetsuri123
avatar
Joined: 26 Dec 2020
Last visit: 15 May 2021
Posts: 7
Own Kudos:
11
 [1]
Given Kudos: 2
Schools: Rotman MMA "22
Schools: Rotman MMA "22
Posts: 7
Kudos: 11
 [1]
Students in certain group know either English or French or both. If 20 06 Jan 2021, 14:08
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Let E, F and E&F be number of people who speak english, number of people who speak french and people who speak both english and french respectively.

Given -
20% of E = (E) - (E&F)
E&F = 60% of F

To find - ratio of E&F to total speakers

20% x E = E - E&F {Given}
hence E&F = (80/100) x E ---- (1)

E&F = (60/100) x F {Given} -----(2)

From (1) and (2), we get

E&F = (60/100)x F = (80/100) x E

Hence F = 80/60 x E = 8/6 x E

Total number of Speakers = E + F - E&F = E + (8/6)E - (8/10)E = E(1 + 8/6 - 8/10)

Ratio = (E&F) / (Total Number of Speakers) = (80/100)E /(1 + 8/6 - 8/10)E = (8/10)/(1 + 8/6 - 8/10)
User avatar
BAA5
User avatar
Joined: 05 Jun 2021
Last visit: 05 Dec 2023
Posts: 112
Own Kudos:
78
Given Kudos: 77
GMAT 1: 750 Q49 V44
Products:
My Reviews
GMAT 1: 750 Q49 V44
Posts: 112
Kudos: 78
Students in certain group know either English or French or both. If 20 13 Nov 2021, 08:04
Kudos
Add Kudos
Bookmarks
Bookmark this Post
The easiest approach according to me is translating percentages into fractions or rations
so 20% of english speakers know only English- 80% know both or 4/5 of English speakers know both English and French
So I divide the group as x and 4x
Similarly 60% of French speakers know English so again 3y know both languages and 2y know only french
To solve quickly, take LCM of 4x and 3y 12 and then find out x=(3, if 4x=12) and 2y=(8 if 3y = 12) values from the same
we will quickly be able to know that we have a total of 23 people and 12 speak both languages
Hence answer is B
User avatar
ajay0520
User avatar
Joined: 21 Oct 2023
Last visit: 14 May 2025
Posts: 56
Own Kudos:
40
Given Kudos: 26
Posts: 56
Kudos: 40
Students in certain group know either English or French or both. If 20 03 May 2025, 03:49
Kudos
Add Kudos
Bookmarks
Bookmark this Post
there has been a lots of confusing explaination about this question, so i thought of adding one more.
we all are clear from question that 0.8E=0.6F (if youre not sure about it, feel free ask)
hence lets find a number that is lcm of both 8 and 6 as the number of person who knows both. which is 24.
which means 0.8E=0.6F=24 which means only 0.2E=6 and 0.4F=16.
question says there are no one who dont know both.
hence total no of people = 24+16+6= 46

hence, part of the entire group knows both languages
=both known/ total no of people
=24/46
=12/23
Moderators:
Bunuel
Math Expert
101568 posts
Krunaal
PS Forum Moderator
585 posts