BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Sets sum

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Legendary Member
Posts: 934
Joined: Tue Nov 09, 2010 5:16 am
Location: AAMCHI MUMBAI LOCAL
Thanked: 63 times
Followed by:14 members

Sets sum

by [email protected] » Thu Jun 09, 2011 10:51 pm
In a group of 68 students, each student is registered for at least one of three classes - History, Math and English. Twenty-five students are registered for History, twenty-five students are registered for Math, and thirty-four students are registered for English. If only three students are registered for all three classes, how many students are registered for exactly two classes?


Guyzzz... according to me the answer comes out to 19. Is it correct???
IT IS TIME TO BEAT THE GMAT

LEARNING, APPLICATION AND TIMING IS THE FACT OF GMAT AND LIFE AS WELL... KEEP PLAYING!!!

Whenever you feel that my post really helped you to learn something new, please press on the 'THANK' button.
Top
Source: — Problem Solving |
Legendary Member
Posts: 1448
Joined: Tue May 17, 2011 9:55 am
Location: India
Thanked: 375 times
Followed by:53 members

by Frankenstein » Thu Jun 09, 2011 11:31 pm
Hi,
e1 - no.of students registered for exactly one class
e2 - no.of students registered for exactly two classes
e3 - no.of students registered for exactly three classes
e1+e2+e3 = 68
e1+2e2+3e3 = 25+25+34=84
So, e2+2e3 = 16
but, e3 = 3. So, e2 = 10
Cheers!

Things are not what they appear to be... nor are they otherwise
Top
User avatar
Legendary Member
Posts: 1309
Joined: Mon Apr 04, 2011 5:34 am
Location: India
Thanked: 310 times
Followed by:123 members
GMAT Score:750

by cans » Fri Jun 10, 2011 6:11 am
total 68
H,M,E
H=25;M=25;E=34
H&m&e=3
exactly 1 + exactly 2 + exactly 3 =total = 68
also exactly 1 + 2*exactly 2 + 3*exactly3 = one each = 25+25+34 = 84
Thus solving, exactly2 = 10
If my post helped you- let me know by pushing the thanks button ;)

Contact me about long distance tutoring!
[email protected]

Cans!!
Top
Junior | Next Rank: 30 Posts
Posts: 26
Joined: Thu Jun 02, 2011 7:21 am

by finites » Fri Jun 10, 2011 11:16 am
Frankenstein wrote:Hi,
e1 - no.of students registered for exactly one class
e2 - no.of students registered for exactly two classes
e3 - no.of students registered for exactly three classes
e1+e2+e3 = 68
e1+2e2+3e3 = 25+25+34=84
So, e2+2e3 = 16
but, e3 = 3. So, e2 = 10

Would like to know how did we arrive at e1+2e2+3e3 = 25 + 25 + 34 ?
Top
User avatar
GMAT Instructor
Posts: 3225
Joined: Tue Jan 08, 2008 2:40 pm
Location: Toronto
Thanked: 1710 times
Followed by:614 members
GMAT Score:800

by Stuart@KaplanGMAT » Fri Jun 10, 2011 11:28 am
Many of the questions with which you're practicing have been previously discussed on this board. The BTG search tool is very useful.

Here are a couple of threads discussing this question:

https://www.beatthegmat.com/mgmat-cat-2- ... 47933.html

and

https://www.beatthegmat.com/3-sets-prob-t35079.html

the second even has a pretty picture!

edit: typo!
Last edited by Stuart@KaplanGMAT on Fri Jun 10, 2011 2:14 pm, edited 1 time in total.
Image

Stuart Kovinsky | Kaplan GMAT Faculty | Toronto

Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course
Top
Junior | Next Rank: 30 Posts
Posts: 26
Joined: Thu Jun 02, 2011 7:21 am

by finites » Fri Jun 10, 2011 1:56 pm
Stuart Kovinsky wrote:Many of the questions with which you're practicing have been previously discussed on this board. The BTG search tool is very useful.

Here are a couple of threads discussion this question:

https://www.beatthegmat.com/mgmat-cat-2- ... 47933.html

and

https://www.beatthegmat.com/3-sets-prob-t35079.html

the second even has a pretty picture!
tHank you !
Top
User avatar
Legendary Member
Posts: 934
Joined: Tue Nov 09, 2010 5:16 am
Location: AAMCHI MUMBAI LOCAL
Thanked: 63 times
Followed by:14 members

by [email protected] » Sun Jun 12, 2011 9:01 pm
Thank you so much guyzz.. for a wonderful explanation!!!!
IT IS TIME TO BEAT THE GMAT

LEARNING, APPLICATION AND TIMING IS THE FACT OF GMAT AND LIFE AS WELL... KEEP PLAYING!!!

Whenever you feel that my post really helped you to learn something new, please press on the 'THANK' button.
Top
Post new topic Post Reply
• Page 1 of 1