Last visit was: 30 Apr 2026, 04:31 It is currently 30 Apr 2026, 04:31
Home
Messages
Tests
Schools
Events
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: 30 Apr 2026
Posts: 110,007
Own Kudos:
812,068
 [10]
Given Kudos: 105,960
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: 110,007
Kudos: 812,068
 [10]
In a class of 50 students, 10 did not opt for math. 15 did not opt for 19 Aug 2015, 22:51
Kudos
Add Kudos
10
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

25% (medium)

Question Stats:

72% (01:18) correct 28% (01:26) wrong based on 370 sessions

History

Date
Time
Result
Not Attempted Yet
In a class of 50 students, 10 did not opt for math. 15 did not opt for science and 2 did not opt for either. How many students of the class opted for both math and science?

A. 23
B. 25
C. 27
D. 37
E. 48


Kudos for a correct solution.
ShowHide Answer
Official Answer
C
Most Helpful Reply
User avatar
rocky620
User avatar
Retired Moderator
Joined: 10 Nov 2018
Last visit: 11 May 2023
Posts: 480
Own Kudos:
626
 [5]
Given Kudos: 229
Location: India
Concentration: General Management, Strategy
Schools: IIMA PGPX'22 IIMB EPGP'22 IIMC PGPEX'22 ISB'22
GMAT 1: 590 Q49 V22
WE:Other (Retail: E-commerce)
Schools: IIMA PGPX'22 IIMB EPGP'22 IIMC PGPEX'22 ISB'22
GMAT 1: 590 Q49 V22
Posts: 480
Kudos: 626
 [5]
In a class of 50 students, 10 did not opt for math. 15 did not opt for 31 Jul 2019, 03:22
5
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Please let me know is teh below Approach Is correct:

10 did not opt for maths, so 40 Opted for it
15 did not opt for science, so 35 Opted for it
2 did not opt for anything, so only 48 opted for the subjects:

So, 48 = 40+35-MnS
MnS=75-48=27
General Discussion
User avatar
jimmy02
User avatar
Joined: 04 Apr 2015
Last visit: 02 Sep 2018
Posts: 37
Own Kudos:
19
 [1]
Given Kudos: 31
Posts: 37
Kudos: 19
 [1]
In a class of 50 students, 10 did not opt for math. 15 did not opt for 19 Aug 2015, 22:57
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
10 did not opt for math means 40 opt for math.
15 did not opt for science means 35 opt for science.
2 did not opt for both means 8 opt for science but not maths & 13 did not opt for science but for maths.
So required ans is 27 opt for both.

Ans C.

Jimmy
User avatar
peachfuzz
User avatar
Joined: 28 Feb 2014
Last visit: 27 Jan 2018
Posts: 268
Own Kudos:
369
Given Kudos: 132
Location: United States
Concentration: Strategy, General Management
Products:
My Reviews
Posts: 268
Kudos: 369
In a class of 50 students, 10 did not opt for math. 15 did not opt for 20 Aug 2015, 09:42
Kudos
Add Kudos
Bookmarks
Bookmark this Post
50 students total
10 did not opt for math
15 did not opt for science
2 did not opt for either

Total of 40 students in math and 13 did not opt for sci but did for math
40-13=27

27 students of the class opted for both math and science

Answer:
C. 27
User avatar
mathivanan
User avatar
Joined: 10 Jun 2015
Last visit: 20 Sep 2015
Posts: 83
Own Kudos:
79
Posts: 83
Kudos: 79
In a class of 50 students, 10 did not opt for math. 15 did not opt for 20 Aug 2015, 11:17
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
In a class of 50 students, 10 did not opt for math. 15 did not opt for science and 2 did not opt for either. How many students of the class opted for both math and science?

A. 23
B. 25
C. 27
D. 37
E. 48


Kudos for a correct solution.
Show more

let me use venn diagram (two intersecting circles, one for students who opted for math and one for who opted for sci)
Let me use the universal set also. U-(AUB)=students who did not opt for both, that is equal to 2.
Therefore, students who opted for only math are 13 and students opted for only sci are 8
It implies student who opted for both the subjects will be 50-(13+8+2)=27
Hence, the correct option is C
User avatar
chanakya84
User avatar
Joined: 08 Sep 2010
Last visit: 08 Feb 2026
Posts: 44
Own Kudos:
78
 [4]
Given Kudos: 22
GMAT 1: 630 Q46 V30
Posts: 44
Kudos: 78
 [4]
In a class of 50 students, 10 did not opt for math. 15 did not opt for 10 Oct 2015, 12:39
4
Kudos
Add Kudos
Bookmarks
Bookmark this Post
[img]
Attachment:
pic.png
[/img]

I have followed a grid approach. Please see the attached image for explanation.

Numbers in Green - Data provided
Numbers in Black - Data calculated

Thanks,
Chanakya
Attachments

pic.png
pic.png [ 4.72 KiB | Viewed 58538 times ]

User avatar
Paras96
User avatar
Joined: 11 Sep 2022
Last visit: 30 Dec 2023
Posts: 455
Own Kudos:
338
Given Kudos: 2
Location: India
Paras: Bhawsar
GMAT 1: 590 Q47 V24
GMAT 2: 580 Q49 V21
GMAT 3: 700 Q49 V35
GPA: 3.2
WE:Project Management (Other)
GMAT 3: 700 Q49 V35
Posts: 455
Kudos: 338
In a class of 50 students, 10 did not opt for math. 15 did not opt for 17 Aug 2023, 05:12
Kudos
Add Kudos
Bookmarks
Bookmark this Post
In a class of 50 students, 10 did not opt for math. 15 did not opt for science and 2 did not opt for either. How many students in the class opted for both math and science?

Students who did not opt only math = 10 - 2 = 8

Students who did not opt only science = 15 - 2 = 13

Students who obtained math or science = 50 - 2 =48 = Students who opt only math + students who opt only science + students who opt math and science

=> 48 = (50-10) + (50-15) - x
=> x = 27

Hence C
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 39,003
Own Kudos:
1,122
Posts: 39,003
Kudos: 1,122
In a class of 50 students, 10 did not opt for math. 15 did not opt for 15 Dec 2024, 04:18
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.
Moderators:
Bunuel
Math Expert
110007 posts
Krunaal
Tuck School Moderator
852 posts