GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 24 Jan 2019, 05:17

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.

Close

Request Expert Reply

Confirm Cancel
Events & Promotions in January
PrevNext
SuMoTuWeThFrSa
303112345
6789101112
13141516171819
20212223242526
272829303112
Open Detailed Calendar
  • Key Strategies to Master GMAT SC

     January 26, 2019

     January 26, 2019

     07:00 AM PST

     09:00 AM PST

    Attend this webinar to learn how to leverage Meaning and Logic to solve the most challenging Sentence Correction Questions.
  • Free GMAT Number Properties Webinar

     January 27, 2019

     January 27, 2019

     07:00 AM PST

     09:00 AM PST

    Attend this webinar to learn a structured approach to solve 700+ Number Properties question in less than 2 minutes.

If 3 members are to be selected from a team of x members then what is

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

 
CEO
CEO
User avatar
P
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2726
Location: India
GMAT: INSIGHT
Schools: Darden '21
WE: Education (Education)
Reviews Badge
If 3 members are to be selected from a team of x members then what is  [#permalink]

Show Tags

New post 01 Apr 2018, 00:05
2
3
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

73% (00:55) correct 27% (01:17) wrong based on 164 sessions

HideShow timer Statistics

If 3 members are to be selected from a group of x members then what is the value of x?

1) If team of 3 members is selected from the group of x members then 30 different combinations of 3 members can be formed with 2 specific members never being together on the team
2) There are a total of 35 ways to make team of 3 members out of team of x members.

Source: www.GMATinsight.com

_________________

Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION

Math Expert
User avatar
V
Joined: 02 Aug 2009
Posts: 7215
Re: If 3 members are to be selected from a team of x members then what is  [#permalink]

Show Tags

New post 01 Apr 2018, 01:17
1
3
If 3 members are to be selected from a group of x members then what is the value of x?

1) If team of 3 members is selected from the group of x members then 30 different combinations of 3 members can be formed with 2 specific members never being together on the team
Selecting 3 members from x =xC3
Selecting 3 when the 2 specific members are together=(x-2)C1... 2 selected from x, the remaining 1 can be selected from remaining x-2.
So cases when the 2 are not together=xC3-(x-2)C1=30...
\(\frac{x(x-1)(x-2)}{6}-(x-2)=30.....(x-2)(x^2-x-6)=180.......(x-2)(x-3)(x+2)=180=4*5*9\)
So x-2=5..x=7
Sufficient


2) There are a total of 35 ways to make team of 3 members out of team of x members.
xC3=35...
\(\frac{x(x-1)(x-2)}{6}=35......x(x-2)(x-1)=5*6*7\)
x=7
Sufficient

D
_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html


GMAT online Tutor

Manager
Manager
avatar
S
Joined: 05 Feb 2016
Posts: 144
Location: India
Concentration: General Management, Marketing
WE: Information Technology (Computer Software)
GMAT ToolKit User
Re: If 3 members are to be selected from a team of x members then what is  [#permalink]

Show Tags

New post 01 Apr 2018, 03:51
GMATinsight wrote:
If 3 members are to be selected from a group of x members then what is the value of x?

1) If team of 3 members is selected from the group of x members then 30 different combinations of 3 members can be formed with 2 specific members never being together on the team
2) There are a total of 35 ways to make team of 3 members out of team of x members.

Source: http://www.GMATinsight.com


we have to find x.

From1 : 2 specific members never being together=Total number of combinations- 2 specific members being together.
Total number of combinations=xC3
2 specific members being together=(x-1)C3
xC3-(x-1)C3=30

Since one equation one variable . So 1 is sufficient.

From2 : xC3=35

Again one equation one variable . So 2 is also sufficient.

No need to find value it will take your time.

So D.
Intern
Intern
avatar
B
Joined: 01 Feb 2018
Posts: 18
Re: If 3 members are to be selected from a team of x members then what is  [#permalink]

Show Tags

New post 08 Apr 2018, 02:22
kunalcvrce wrote:
GMATinsight wrote:
If 3 members are to be selected from a group of x members then what is the value of x?

1) If team of 3 members is selected from the group of x members then 30 different combinations of 3 members can be formed with 2 specific members never being together on the team
2) There are a total of 35 ways to make team of 3 members out of team of x members.

Source: http://www.GMATinsight.com


we have to find x.

From1 : 2 specific members never being together=Total number of combinations- 2 specific members being together.
Total number of combinations=xC3
2 specific members being together=(x-1)C3
xC3-(x-1)C3=30

Since one equation one variable . So 1 is sufficient.

From2 : xC3=35

Again one equation one variable . So 2 is also sufficient.

No need to find value it will take your time.

So D.



Isnt xC3-(x-1)C3=15??

7C3= 35 and 6C3 =20, or am I wrong?
DS Forum Moderator
avatar
P
Joined: 21 Aug 2013
Posts: 1435
Location: India
Premium Member
Re: If 3 members are to be selected from a team of x members then what is  [#permalink]

Show Tags

New post 08 Apr 2018, 03:33
1
truongvu31 wrote:
kunalcvrce wrote:
GMATinsight wrote:
If 3 members are to be selected from a group of x members then what is the value of x?

1) If team of 3 members is selected from the group of x members then 30 different combinations of 3 members can be formed with 2 specific members never being together on the team
2) There are a total of 35 ways to make team of 3 members out of team of x members.

Source: http://www.GMATinsight.com


we have to find x.

From1 : 2 specific members never being together=Total number of combinations- 2 specific members being together.
Total number of combinations=xC3
2 specific members being together=(x-1)C3
xC3-(x-1)C3=30

Since one equation one variable . So 1 is sufficient.

From2 : xC3=35

Again one equation one variable . So 2 is also sufficient.

No need to find value it will take your time.

So D.



Isnt xC3-(x-1)C3=15??

7C3= 35 and 6C3 =20, or am I wrong?



Actually, it shouldnt be (x-1)C3.. The no of ways of selecting 3 out of x, so that two specific members are together on the team = (x-2)C1.. this is because if we have already fixed two members, then we have to select remaining 1 more member out of (x-2).

So it should be xC3 - (x-1)C2 = 30
And you can check: 7C3 - 5C1 = 35-5 = 30
Senior Manager
Senior Manager
avatar
P
Joined: 17 Mar 2014
Posts: 422
GMAT ToolKit User Premium Member Reviews Badge CAT Tests
Re: If 3 members are to be selected from a team of x members then what is  [#permalink]

Show Tags

New post 09 Jan 2019, 12:08
Bunuel,

Is (x-2)C1 correct in chetan2u answer ?
GMAT Club Bot
Re: If 3 members are to be selected from a team of x members then what is &nbs [#permalink] 09 Jan 2019, 12:08
Display posts from previous: Sort by

If 3 members are to be selected from a team of x members then what is

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

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®.