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.

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

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.

A certain university will select 1 of 7 candidates eligible
[#permalink]

Show Tags

05 Jan 2008, 08:39

2

10

00:00

A

B

C

D

E

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?

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" _________________

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.

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
_________________

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?

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.

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 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

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).

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.
_________________