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

It is currently 21 Jan 2019, 08:15

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
  • GMAT Club Tests are Free & Open for Martin Luther King Jr.'s Birthday!

     January 21, 2019

     January 21, 2019

     10:00 PM PST

     11:00 PM PST

    Mark your calendars - All GMAT Club Tests are free and open January 21st for celebrate Martin Luther King Jr.'s Birthday.
  • 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.

From 6 positive numbers and 6 negative numbers, how many gro

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

Hide Tags

 
Intern
Intern
avatar
Joined: 15 Jun 2010
Posts: 9
From 6 positive numbers and 6 negative numbers, how many gro  [#permalink]

Show Tags

New post 15 Apr 2014, 15:42
6
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

63% (01:41) correct 37% (02:01) wrong based on 149 sessions

HideShow timer Statistics

From 6 positive numbers and 6 negative numbers, how many groups of 4 numbers, yielding a positive product, can be formed?

A. 720
B. 625
C. 30
D. 960
E. 255
Retired Moderator
User avatar
Joined: 20 Dec 2013
Posts: 172
Location: United States (NY)
GMAT 1: 640 Q44 V34
GMAT 2: 710 Q48 V40
GMAT 3: 720 Q49 V40
GPA: 3.16
WE: Consulting (Venture Capital)
GMAT ToolKit User Premium Member Reviews Badge
Re: From 6 positive numbers and 6 negative numbers  [#permalink]

Show Tags

New post 15 Apr 2014, 17:31
1
1
Potential combinations of 4 numbers that will yield positive product

++++ 4C6
---- 4C6
++-- 2C6*2C6

4C6 + 4C6 + 2C6*2C6
15 +15 + 15*15 = 255
_________________

MY GMAT BLOG - ADVICE - OPINIONS - ANALYSIS

Veritas Prep GMAT Instructor
User avatar
D
Joined: 16 Oct 2010
Posts: 8803
Location: Pune, India
Re: From 6 positive numbers and 6 negative numbers  [#permalink]

Show Tags

New post 15 Apr 2014, 19:41
2
2
tauchmeister wrote:
Another question, from a set I found here at home.

I don't know from where the source is.

Thanks

From 6 positive numbers and 6 negative numbers,
how many groups of 4 numbers, yielding a
positive product, can be formed?
a) 720
b) 625
c) 30
d) 960
e) 255


When will the product of 4 numbers be positive? It is positive when the number of negative numbers in the product is even i.e. when we have 0 negative numbers or 2 negative numbers or 4 negative numbers.

3 cases:

- 0 negative numbers - All numbers are positive - Selected in 6C4 = 15 ways

- 2 negative numbers - 2 are positive and 2 are negative - Selected in 6C2*6C2 = 15*15 = 225 ways

- 4 negative numbers - All numbers are negative - Selected in 6C4 = 15 ways

Total number of ways = 15 + 225 + 15 = 255

Answer (E)
_________________

Karishma
Veritas Prep GMAT Instructor

Learn more about how Veritas Prep can help you achieve a great GMAT score by checking out their GMAT Prep Options >

Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 9459
Premium Member
Re: From 6 positive numbers and 6 negative numbers, how many gro  [#permalink]

Show Tags

New post 01 Nov 2018, 23:58
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.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

GMAT Club Bot
Re: From 6 positive numbers and 6 negative numbers, how many gro &nbs [#permalink] 01 Nov 2018, 23:58
Display posts from previous: Sort by

From 6 positive numbers and 6 negative numbers, how many gro

  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®.