Author 
Message 
TAGS:

Hide Tags

Manager
Joined: 16 Feb 2011
Posts: 195
Schools: ABCD

A bag has 4 blue, 3 yellow and 2 green balls. The balls of [#permalink]
Show Tags
30 Sep 2012, 09:13
1
This post received KUDOS
10
This post was BOOKMARKED
Question Stats:
51% (02:37) correct
49% (02:08) wrong based on 157 sessions
HideShow timer Statistics
A bag has 4 blue, 3 yellow and 2 green balls. The balls of the same color are identical. In how many ways can a child picks ball(s) out of the bag? He could even decide to pick ZERO balls. A. 60 B. 1260 C. 24 D. 120 E. 9 Can someone please explain why the answer isn't : Option 1: 0 balls  1 way 2. Green balls: (2C0=1)+(2C1=2)+(2C2=1)= 4 ways 3. Yellow Balls: (3C0=1)+(3C1=3)+(3C2=3)+(3C3=1)=8 ways 4. Blue Balls: (4C0=1)+(4C1=4)+(4C2=6)+(4C3=4)+(4C4=1)= 16 ways Total => multply all the numbers abvoe => 512 I am a bit confused.
Official Answer and Stats are available only to registered users. Register/ Login.



Intern
Joined: 02 Nov 2009
Posts: 43
Location: India
Concentration: General Management, Technology
GMAT Date: 04212013
GPA: 4
WE: Information Technology (Internet and New Media)

Re: A bag has 4 blue, 3 yellow and 2 green balls. The balls of [#permalink]
Show Tags
30 Sep 2012, 11:24
4
This post received KUDOS
With the blue ball there are 5 scenarios> 0 blue ball being selected 1 blue ball being selected 2 blue ball being selected 3 blue ball being selected 4 blue ball being selected And for each of these cases there is only one possibilty as they are identical. So there are 5 ways to select the blue ball Same is the case with 3 yellow (for which we have 4 possibilties) and 2 green balls(we have 3 possibilties) so in total 5*4*3 = 60 possibilties..
_________________
KPV



Manager
Joined: 16 Feb 2011
Posts: 195
Schools: ABCD

Re: A bag has 4 blue, 3 yellow and 2 green balls. The balls of [#permalink]
Show Tags
30 Sep 2012, 12:04
Ok. But why can't we do Green balls: (2C0=1)+(2C1=2)+(2C2=1)= 4 ways ? See this thread : ajarcontains6magentaballs139813.htmlThe balls are also identical in the above question. I am confused between these two threads....



Director
Joined: 22 Mar 2011
Posts: 612
WE: Science (Education)

Re: A bag has 4 blue, 3 yellow and 2 green balls. The balls of [#permalink]
Show Tags
30 Sep 2012, 13:24
1
This post received KUDOS
voodoochild wrote: Ok. But why can't we do Green balls: (2C0=1)+(2C1=2)+(2C2=1)= 4 ways ? See this thread : ajarcontains6magentaballs139813.htmlThe balls are also identical in the above question. I am confused between these two threads.... All the Green balls are identical. We don't care which one(s) was(were) chosen, only how many. We are interested in the final "statistics": how many Green balls were chosen? We have 3 possibilities: 0, 1, or 2. 2C1 = 2, it's true, but choosing either Green ball, will have the same statistical result: one Green ball was chosen, and we don't care about which one of the two Greens, because they are absolutely identical!
_________________
PhD in Applied Mathematics Love GMAT Quant questions and running.



Current Student
Joined: 06 Sep 2013
Posts: 1997
Concentration: Finance

Re: A bag has 4 blue, 3 yellow and 2 green balls. The balls of [#permalink]
Show Tags
16 Apr 2014, 14:23
I tried this problem using anagram grid 9! / 4! 3 ! 2! = 1260 Does anyone know what i'm missing to get to 60 as an answer here? Thanks! Cheers J



Math Expert
Joined: 02 Sep 2009
Posts: 39753

Re: A bag has 4 blue, 3 yellow and 2 green balls. The balls of [#permalink]
Show Tags
18 Apr 2014, 11:10
jlgdr wrote: A bag has 4 blue, 3 yellow and 2 green balls. The balls of the same color are identical. In how many ways can a child picks ball(s) out of the bag? He could even decide to pick ZERO balls. A. 60 B. 1260 C. 24 D. 120 E. 9 I tried this problem using anagram grid 9! / 4! 3 ! 2! = 1260 Does anyone know what i'm missing to get to 60 as an answer here? Thanks! Cheers J We are not asked to find the number of arrangements of 4 blue, 3 yellow and 2 green balls, which would be 9!/(4!3!2!). We are asked to find the number of selections from 4 blue, 3 yellow and 2 green balls, when there can be any number of balls selected from 0 to 9. A bag has 4 blue, 3 yellow and 2 green balls. The balls of the same color are identical. In how many ways can a child picks ball(s) out of the bag? He could even decide to pick ZERO balls. A. 60 B. 1260 C. 24 D. 120 E. 9 In a selection there can be: 0, 1, 2, 3, or 4 blue balls, so 5 cases; 0, 1, 2, or 3 yellow balls, so 4 cases; 0, 1, or 2 green balls, so 3 cases. Total 5*4*3=60 selections. Answer: A. Hope it's clear.
_________________
New to the Math Forum? Please read this: All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



Current Student
Joined: 28 Apr 2012
Posts: 306
Location: India
Concentration: Finance, Technology
GMAT 1: 650 Q48 V31 GMAT 2: 770 Q50 V47
WE: Information Technology (Computer Software)

Re: A bag has 4 blue, 3 yellow and 2 green balls. The balls of [#permalink]
Show Tags
18 Apr 2014, 12:34
please go thru below link: mathcombinatorics87345.html#p785179You can solve in seconds: (4+1)*(3+1)*(2+1) = 5*4*3 = 60
_________________
"Appreciation is a wonderful thing. It makes what is excellent in others belong to us as well." ― Voltaire
Press Kudos, if I have helped. Thanks!



GMAT Club Legend
Joined: 09 Sep 2013
Posts: 16024

Re: A bag has 4 blue, 3 yellow and 2 green balls. The balls of [#permalink]
Show Tags
19 Jul 2015, 20:05
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 Legend
Joined: 09 Sep 2013
Posts: 16024

Re: A bag has 4 blue, 3 yellow and 2 green balls. The balls of [#permalink]
Show Tags
03 Mar 2017, 10:36
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




Re: A bag has 4 blue, 3 yellow and 2 green balls. The balls of
[#permalink]
03 Mar 2017, 10:36








Similar topics 
Author 
Replies 
Last post 
Similar Topics:




A bag has 32 yellow, red, blue and green balls. If one ball

rohan2345 
9 
27 Jun 2017, 00:16 



There are 6 red balls and 4 blue balls in a jar. If 2 balls are select

MathRevolution 
5 
26 May 2017, 00:19 

10


A box contains 1 blue ball, 1 green ball, 1 yellow ball

GMATPrepNow 
3 
13 Jan 2017, 04:07 

5


A has to pick a ball from a bag with 3 red & 3 blue balls.

idiot 
12 
10 Apr 2017, 04:05 

75


Rich has 3 green, 2 red and 3 blue balls in a bag. He

young_gun 
30 
22 Feb 2017, 03:31 



