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

It is currently 30 Aug 2014, 16:43

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

There are six balls in a box. Three balls are marked with 1,

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
SVP
SVP
User avatar
Joined: 03 Feb 2003
Posts: 1613
Followers: 5

Kudos [?]: 44 [0], given: 0

There are six balls in a box. Three balls are marked with 1, [#permalink] New post 07 Aug 2003, 01:44
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
There are six balls in a box. Three balls are marked with 1, three with 0. Three balls are taken at random without repetitions. In how many combinations will the product of the digits on the balls equal to 0?
Manager
Manager
avatar
Joined: 24 Jun 2003
Posts: 94
Location: Moscow
Followers: 1

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

answer [#permalink] New post 07 Aug 2003, 02:40
The product of three numbers will equal ‘0’ if at least one of the numbers is zero. Another way is to substract a number of combinations when none of the numbers equal zero from a total number of combinations.

A total number of combinations of 3 balls out of 6 is 6C3=20. The number of combinations of all ones is 3C3=1. Thus, the number of combinations of none zero out of three is 20-1=19.

Double check the longer way (at least)

Number of combinations of exactly one zero (two '1'): 3C1*3C2=9
Number of combinations of exactly two zeros (one '1'): 3C2*3C1=9
Number of combinations of exactly tree zeros: 3C3=1

Add them all up and the answer is 19.

- Stolyar?
_________________

Respect,

KL

Manager
Manager
avatar
Joined: 24 Jun 2003
Posts: 94
Location: Moscow
Followers: 1

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

Idea [#permalink] New post 07 Aug 2003, 10:42
Guys,

We are paying so much attention to combinations here. It is great, but I must say that another topic - promultation is a kind of deep forest for me.

If someone has any questions on promultation that he would like to post here, I would be grateful.
_________________

Respect,

KL

Director
Director
avatar
Joined: 03 Jul 2003
Posts: 656
Followers: 2

Kudos [?]: 13 [0], given: 0

GMAT Tests User
 [#permalink] New post 07 Aug 2003, 12:52
Saylor

Are you sure the answer is 19. We didn't have 6 distinct balls.
We two type of three balls. Then the combination must be much
smaller than 19.

I don't have mathametical expression for the problem.
But here is my logical explanation.

Following are the possible combinations:
111
110
100
000

Because it is combinaiton problem the oder is not important.
So, 110 and 101 are one at the same.

Thus, the answer is 3!
SVP
SVP
User avatar
Joined: 03 Feb 2003
Posts: 1613
Followers: 5

Kudos [?]: 44 [0], given: 0

 [#permalink] New post 08 Aug 2003, 01:21
N(product is zero)=N(total)-N(product is 1)

N(total)=6C3=20
N(product is 1)=3C3=1

20-1=19

what is wrong? I use combinations. Where order is not important.
  [#permalink] 08 Aug 2003, 01:21
    Similar topics Author Replies Last post
Similar
Topics:
A box contains 100 balls, numbered from 1 to 100. If three girikorat 4 14 Oct 2006, 05:43
A box contains 100 balls, numbered from 1 to 100. If three girikorat 3 22 Sep 2006, 23:52
A box contains 100 balls, numbered from 1 to 100. If three minagmat 15 17 Sep 2006, 07:03
A box contains 100 balls, numbered from 1 to 100. If three Matador 4 15 Apr 2006, 20:02
A box contains 100 balls numbered from 1 to 100. If three kimmyg 6 18 Oct 2005, 08:06
Display posts from previous: Sort by

There are six balls in a box. Three balls are marked with 1,

  Question banks Downloads My Bookmarks Reviews Important topics  


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

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®.