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

 It is currently 22 Jan 2019, 08:49

### 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

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 January
PrevNext
SuMoTuWeThFrSa
303112345
6789101112
13141516171819
20212223242526
272829303112
Open Detailed Calendar
• ### The winners of the GMAT game show

January 22, 2019

January 22, 2019

10:00 PM PST

11:00 PM PST

In case you didn’t notice, we recently held the 1st ever GMAT game show and it was awesome! See who won a full GMAT course, and register to the next one.
• ### 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.

# A certain university will select 1 of 7 candidates eligible

Author Message
VP
Joined: 22 Nov 2007
Posts: 1039
A certain university will select 1 of 7 candidates eligible  [#permalink]

### Show Tags

05 Jan 2008, 08:39
2
10
00:00

Difficulty:

5% (low)

Question Stats:

88% (00:40) correct 12% (00:57) wrong based on 490 sessions

### HideShow timer Statistics

A certain university will select 1 of 7 candidates eligible to fill a position in the mathematics department and 2 of 10 candidates eligible to fill 2 identical positions in the computer science department. If none of the candidates is eligible for a position in both departments, how many different sets of 3 candidates are there to fill the 3 positions?

A. 42
B. 70
C. 140
D. 165
E. 315

OPEN DISCUSSION OF THIS QUESTION IS HERE: a-certain-university-will-select-1-of-7-candidates-eligible-103273.html
CEO
Joined: 17 Nov 2007
Posts: 3438
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40

### Show Tags

05 Jan 2008, 08:48
5
E

N=7C1*2C10=7*45=315
we use 2C10 rather than 2P10 because "2 of 10 candidates eligible to fill 2 identical positions in the computer science department"
_________________

HOT! GMAT TOOLKIT 2 (iOS) / GMAT TOOLKIT (Android) - The OFFICIAL GMAT CLUB PREP APP, a must-have app especially if you aim at 700+ | Limited GMAT/GRE Math tutoring in Chicago

Senior Manager
Joined: 19 Nov 2007
Posts: 396

### Show Tags

06 Jan 2008, 17:20
well , I could get the OA, but can someone please explain what is the significance of this statement
"If none of the candidates is eligible for a position in both departments",.
I thoght we were finding combinations of eligible candidates!
_________________

-Underline your question. It takes only a few seconds!
-Search before you post.

SVP
Joined: 04 May 2006
Posts: 1656
Schools: CBS, Kellogg

### Show Tags

06 Jan 2008, 17:41
4
1
vscid wrote:
well , I could get the OA, but can someone please explain what is the significance of this statement
"If none of the candidates is eligible for a position in both departments",.
I thoght we were finding combinations of eligible candidates!

it means that the candidates of science department can not be eligible for the math department. Two groups are saperate, no overlap
_________________
SVP
Joined: 29 Mar 2007
Posts: 2421

### Show Tags

06 Jan 2008, 19:32
marcodonzelli wrote:
A certain university will select 1 of 7 candidates eligible to fill a position in the mathematics department and 2 of 10 candidates eligible to fill 2 identical positions in the computer science department. If none of the candidates is eligible for a position in both departments, how many different sets of 3 candidates are there to fill the 3 positions?

A. 42
B. 70
C. 140
D. 165
E. 315

7/1!*6! --> 7 * 10!/2!*8! --> 5*9 --> 5*9*7 =315
Senior Manager
Joined: 19 Nov 2007
Posts: 396

### Show Tags

07 Jan 2008, 14:54
sondenso wrote:
vscid wrote:
well , I could get the OA, but can someone please explain what is the significance of this statement
"If none of the candidates is eligible for a position in both departments",.
I thoght we were finding combinations of eligible candidates!

it means that the candidates of science department can not be eligible for the math department. Two groups are saperate, no overlap

got it!
had got confused with the wording.
thanks!
_________________

-Underline your question. It takes only a few seconds!
-Search before you post.

Manager
Joined: 27 Oct 2008
Posts: 177

### Show Tags

27 Sep 2009, 09:51
A certain university will select 1 of 7 candidates eligible to fill a position in the mathematics department and 2 of 10 candidates eligible to fill 2 identical positions in the computer science department. If none of the candidates is eligible for a position in both departments, how many different sets of 3 candidates are there to fill the 3 positions?

A. 42
B. 70
C. 140
D. 165
E. 315

Ans: 315

7C1 * 10C2
Manager
Joined: 17 Aug 2009
Posts: 175

### Show Tags

09 Dec 2009, 08:20
This can be a tricky question in terms of wording. As we have to find out the different sets of both, we need to multiply each of the combinations.

Therefore 7C1 * 10C2 = 315
Intern
Joined: 21 Feb 2010
Posts: 23
Location: Ukraine

### Show Tags

24 Apr 2010, 13:09
is it for real 700-Level Question????
Intern
Joined: 28 Aug 2012
Posts: 7

### Show Tags

02 Oct 2012, 00:18
GMATBLACKBELT wrote:
marcodonzelli wrote:
A certain university will select 1 of 7 candidates eligible to fill a position in the mathematics department and 2 of 10 candidates eligible to fill 2 identical positions in the computer science department. If none of the candidates is eligible for a position in both departments, how many different sets of 3 candidates are there to fill the 3 positions?

A. 42
B. 70
C. 140
D. 165
E. 315

7/1!*6! --> 7 * 10!/2!*8! --> 5*9 --> 5*9*7 =315

-----------------------------------------------------------------------
Can you please explain why is it 7C1 ?
Math Expert
Joined: 02 Sep 2009
Posts: 52386

### Show Tags

02 Oct 2012, 00:30
2
2
Weirdo2989 wrote:
GMATBLACKBELT wrote:
marcodonzelli wrote:
A certain university will select 1 of 7 candidates eligible to fill a position in the mathematics department and 2 of 10 candidates eligible to fill 2 identical positions in the computer science department. If none of the candidates is eligible for a position in both departments, how many different sets of 3 candidates are there to fill the 3 positions?

A. 42
B. 70
C. 140
D. 165
E. 315

7/1!*6! --> 7 * 10!/2!*8! --> 5*9 --> 5*9*7 =315

-----------------------------------------------------------------------
Can you please explain why is it 7C1 ?

A certain university will select 1 of 7 candidates eligible to fill a position in the mathematics department and 2 of 10 candidates eligible to fill 2 identical positions in the computer science department. If none of the candidates is eligible for a position in both departments, how many different sets of 3 candidates are there to fill the 3 positions?

A. 42
B. 70
C. 140
D. 165
E. 315

As "none of the candidates is eligible for a position in both departments" then we have 7+10=17 candidates.

$$C^1_7*C^2_{10}=7*45=315$$: $$C^1_7$$ - choosing 1 from 7 and $$C^2_{10}$$ choosing 2 from 10 when order doesn't matter as 2 positions in computer science department are identical (XY is the same as YX).

OPEN DISCUSSION OF THIS QUESTION IS HERE: a-certain-university-will-select-1-of-7-candidates-eligible-103273.html
_________________
Non-Human User
Joined: 09 Sep 2013
Posts: 9464
Re: A certain university will select 1 of 7 candidates eligible  [#permalink]

### Show Tags

01 Aug 2018, 21:55
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Re: A certain university will select 1 of 7 candidates eligible &nbs [#permalink] 01 Aug 2018, 21:55
Display posts from previous: Sort by