Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 05 Jul 2015, 19:01

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# Of the students in a certain class 10 can play piano,11 can

 Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:
Senior Manager
Joined: 29 Aug 2005
Posts: 283
Followers: 1

Kudos [?]: 31 [0], given: 0

Of the students in a certain class 10 can play piano,11 can [#permalink]  12 Jun 2008, 23:05
Of the students in a certain class 10 can play piano,11 can play guitar , 14 can play violon
if 3 students can play all three instruments and 20 can play one of the instruments , how many students can play exactly 2 of the instruments

3
6
9
12
15

what is the most optimal way of solving these kind of questions

Mnay thanks
_________________

The world is continuous, but the mind is discrete

Last edited by vd on 13 Jun 2008, 00:11, edited 1 time in total.
Director
Joined: 14 Aug 2007
Posts: 734
Followers: 8

Kudos [?]: 124 [0], given: 0

Re: of the students in a certain class [#permalink]  13 Jun 2008, 00:09
vdhawan1 wrote:
Of the students in a certain class 10 can play piano,11 can play guitar , 10 can play violon
if 3 students can play all the instruments and 20 can play one of the instruments , how many students can play exactly 2 of the instruments

3
6
9
12
15

what is the most optimal way of solving these kind of questions

Mnay thanks

Are you sure there is no typo in the problem?
Senior Manager
Joined: 29 Aug 2005
Posts: 283
Followers: 1

Kudos [?]: 31 [0], given: 0

Re: of the students in a certain class [#permalink]  13 Jun 2008, 00:12
alpha_plus_gamma wrote:
vdhawan1 wrote:
Of the students in a certain class 10 can play piano,11 can play guitar , 10 can play violon
if 3 students can play all the instruments and 20 can play one of the instruments , how many students can play exactly 2 of the instruments

3
6
9
12
15

what is the most optimal way of solving these kind of questions

Mnay thanks

Are you sure there is no typo in the problem?

ya i m sorry there was a typo

i have corrected it now
can u please attempt the problem now

Thanks
_________________

The world is continuous, but the mind is discrete

Manager
Joined: 14 May 2008
Posts: 71
Followers: 1

Kudos [?]: 39 [0], given: 0

Re: of the students in a certain class [#permalink]  13 Jun 2008, 00:28
I suppose It must be A
If 20 students play only 1 instrument than Only three students can play 2 instruments... there are no other ways
However it took me 4 minutes to conclude that the best way to solve this particular task is - just to pick answer choices

What is AO?

Last edited by quantum on 13 Jun 2008, 00:33, edited 1 time in total.
Director
Joined: 14 Aug 2007
Posts: 734
Followers: 8

Kudos [?]: 124 [0], given: 0

Re: of the students in a certain class [#permalink]  13 Jun 2008, 00:30
answer is 3,

14-3 + 11 -3 + 10 -3 = 20 + 3 + x (x is students who can play 2 instruments)
Manager
Joined: 14 Jun 2007
Posts: 170
Location: Vienna, Austria
Followers: 1

Kudos [?]: 5 [0], given: 0

Re: of the students in a certain class [#permalink]  13 Jun 2008, 23:41
friends, can someone explain it with the standard formula " : A + B +C –both – 2* All 3" ? ... maybe i´m just too tired...

cheers
Manager
Joined: 08 Jun 2008
Posts: 51
Followers: 0

Kudos [?]: 9 [0], given: 0

Re: of the students in a certain class [#permalink]  18 Jun 2008, 05:20
Yep here it is with the standard formula if u wish
might not be the shortest

let X be who play guitar and violin and NOT piano
Let Y be who play violin and piano and NOT guitar
Let Z be who play guitar and piano and NOT violin

so ( 11 - x - z - 3 (who play all 3) ) will be ppl who play only guitar
similarly ( 11-x-z) who play only violin
and ( 7-y-z) who play only piano

add all the 3 above which should equal to 20

solve for (x + y + z ) which is equal to 3
Re: of the students in a certain class   [#permalink] 18 Jun 2008, 05:20
Similar topics Replies Last post
Similar
Topics:
60% of the students in a certain class like playing computer 2 04 Sep 2008, 22:55
Of the students in a certain class, 10 had taken a course in 0 25 Aug 2008, 23:37
in how many ways can you seat 3 students in a row of 10 4 07 Nov 2007, 14:01
Q10: If each of the students in a certain mathematics class 4 09 Jul 2007, 19:25
3 Of a group of people, 10 play piano, 11 play guitar, 14 play 27 21 Apr 2006, 02:44
Display posts from previous: Sort by

# Of the students in a certain class 10 can play piano,11 can

 Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group and phpBB SEO Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.