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

It is currently 24 Oct 2014, 21:44

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

Bag A contains red, white and blue marbles such that the red

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
avatar
Joined: 13 Jun 2005
Posts: 29
Followers: 0

Kudos [?]: 4 [0], given: 0

Bag A contains red, white and blue marbles such that the red [#permalink] New post 29 Jun 2007, 14:38
2
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  75% (hard)

Question Stats:

51% (02:47) correct 49% (02:14) wrong based on 97 sessions
Bag A contains red, white and blue marbles such that the red to white marble ratio is 1:3 and the white to blue marble ratio is 2:3. Bag B contains red and white marbles in the ratio of 1:4. Together, the two bags contain 30 white marbles. How many red marbles could be in bag A?

A. 1
B. 3
C. 4
D. 6
E. 8

OPEN DISCUSSION OF THIS QUESTION IS HERE: bag-a-contains-red-white-and-blue-marbles-such-that-the-red-to-127477.html
[Reveal] Spoiler: OA
Kaplan GMAT Prep Discount CodesKnewton GMAT Discount CodesManhattan GMAT Discount Codes
Intern
Intern
avatar
Joined: 28 Dec 2006
Posts: 13
Followers: 0

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

 [#permalink] New post 29 Jun 2007, 23:35
is there a strategy for this....i solved by brute force.

# white marbles in A + # white marbles in B = 30
# white marbles in A is div 3
# white marbles in B is div 4

Bag A..................Bag B
30 w, 10 r...........0 w, 0 r
18 w, 6 r...........12 w, 3 r

6 red marbles in A works
Director
Director
User avatar
Joined: 09 Aug 2006
Posts: 529
Followers: 2

Kudos [?]: 25 [0], given: 0

 [#permalink] New post 30 Jun 2007, 12:14
Even I went by brute force ;

Its only when red marbles in Bag A are 6, the # of White marbles in A is 18 and thus # of white marbles in B is 12 which is Div by 4. For rest of other %s # of white marbles in B is not div by 4. hence 6.
3 KUDOS received
Senior Manager
Senior Manager
User avatar
Joined: 06 Jul 2006
Posts: 295
Location: SFO Bay Area
Schools: Berkeley Haas
Followers: 2

Kudos [?]: 33 [3] , given: 0

Re: PS: Marble Ratios [#permalink] New post 01 Feb 2008, 17:30
3
This post received
KUDOS
# of Red marbles in Bag A can be either 2 or 6. No 2 in the choices, so 6. D.

Explanation
Bag A:
R:W:B = 2:6:9

Bag B
R:W = 1:4

6X + 4Y = 30 i.e 3X + 2Y = 15

X has to be odd to make an odd sum from the eq.
X = 1 , Y = 6 OR X = 3, Y = 3

So R can be 2X i.e 2 or 6.
_________________

-------------------------------------------------------------
When you come to the end of your rope, tie a knot and hang on.

SVP
SVP
avatar
Joined: 28 Dec 2005
Posts: 1593
Followers: 2

Kudos [?]: 75 [0], given: 2

Re: PS: Marble Ratios [#permalink] New post 01 Feb 2008, 18:15
white(a)+white(b) = 30

white(a)=3*red(a)
white(b)=4*red(b)

3*red(a) + 4*red(b) = 30

now just see what number from the answer choices work, i.e. plug in the answer choices for red(a) and see if red(b) comes out to an integer value. Lets try a, 1:

3*1 + 4*red(b)=30 =>red(b) = 27/4 , which is not an integer and so cant be the answer.

The only value that works is 6.
2 KUDOS received
Senior Manager
Senior Manager
avatar
Joined: 26 Jan 2008
Posts: 267
Followers: 2

Kudos [?]: 74 [2] , given: 1

Re: Marbles Bag A and Bag B [#permalink] New post 24 Feb 2008, 16:42
2
This post received
KUDOS
Manbehindthecurtain wrote:
Bag A contains red, white and blue marbles such that the red to white marble ratio is 1:3 and the white to blue marble ratio is 2:3. Bag B contains red and white marbles in the ratio of 1:4. Together, the two bags contain 30 white marbles. How many red marbles could be in bag A?

This was a MGMAT CAT question. Can you tell me how to solve it with algebra?

1
3
4
6
8


(D) 6

I'd rather use basic ratio arithmetic for a problem like this. I imagine algebra will be a little tedious.

Bag A:
R:W = 1:3; and W:B = 2:3
R:W:B = 2:6:9 -- (I)

Bag B:
R:W = 1:4

Given: there are 30 white marbles.

If we are to split this between the two bags, the split amounts must be multiples of 6 and 4, respectively. That is, [number of white marbles in Bag A, number of white marbles in Bag B] could be either [6, 24] or [18, 12]. Substitute both values of 6 and 18 white marbles in ratio (I) above and you'll see that in Bag A, you can have either 2 or 6 red marbles. Hence (D).
_________________

My GMAT debrief

1 KUDOS received
Intern
Intern
avatar
Joined: 23 Jun 2008
Posts: 2
Followers: 0

Kudos [?]: 1 [1] , given: 0

Re: Ratio question [#permalink] New post 01 Jul 2008, 10:48
1
This post received
KUDOS
6

Bag A = 2x (Red), 6x (White) and 9x (Blue)
Bag B = x(Red), 4x (white)

6x + 4x = 30
x= 3
Red in Bag A = 2x = 6
1 KUDOS received
Intern
Intern
avatar
Joined: 25 Jun 2008
Posts: 13
Followers: 0

Kudos [?]: 2 [1] , given: 0

Re: Ratio question [#permalink] New post 01 Jul 2008, 22:53
1
This post received
KUDOS
i think u have assumed that both the bags contain equal no balls ( x is the total no of balls in the bag). The euation should be 6x+4y=30
Senior Manager
Senior Manager
User avatar
Joined: 07 Jan 2008
Posts: 418
Followers: 3

Kudos [?]: 70 [0], given: 0

Re: Ratio question [#permalink] New post 01 Jul 2008, 23:21
rajesh04 wrote:
From Manhattan CAT - 3

Bag A contains red, white and blue marbles such that the red to white marble ratio is 1:3 and the white to blue marble ratio is 2:3. Bag B contains red and white marbles in the ratio of 1:4. Together, the two bags contain 30 white marbles. How many red marbles could be in bag A?
1)1
2)3
3)4
4)6
5)8

Sorry wrong forum!!



Number of reds in A # number of red in B. So can not assume Xa=Xb (here I call Y)
6x+4y =30
==> x=3, y=3 (Ra=6)
or x =1, y=6 (Ra=2)

D is best answer.
Manager
Manager
avatar
Joined: 22 Sep 2008
Posts: 124
Followers: 1

Kudos [?]: 37 [0], given: 0

Re: Zumit PS 025 [#permalink] New post 22 Sep 2008, 02:25
Is it 6 red balls in A?

If there are 6 red balls in A , then there will be 18 while balls in A , leaving 12 (30 - 12) white balls for B .

Now we can divide 12 by 4 .. so i will go for this answer.

for all other option we will not get white balls values ,so that it will be divide by 4.. (keeping we have 1:4ratio in bag b)

Thanks
Vishal Shah
Director
Director
avatar
Joined: 14 Aug 2007
Posts: 735
Followers: 7

Kudos [?]: 104 [0], given: 0

Re: Zumit PS 025 [#permalink] New post 22 Sep 2008, 05:24
dancinggeometry wrote:
Bag A contains red, white and blue marbles such that the red to white marble ratio is 1:3 and the white to blue marble ratio is 2:3. Bag B contains red and white marbles in the ratio of 1:4. Together, the two bags contain 30 white marbles. How many red marbles could be in bag A?

1
3
4
6
8


W1 + W2 = 30

Where W1 is divisible by 6 and w2 is divisible by 4
6 12 18 24
4 8 12 16 20 24 28

only 18 and 12 can be correct values.
W1=18

if W1=18, Red=6 (1:3)

D
SVP
SVP
avatar
Joined: 17 Jun 2008
Posts: 1578
Followers: 12

Kudos [?]: 186 [0], given: 0

Re: Zumit PS 025 [#permalink] New post 22 Sep 2008, 10:06
If x is number of white marbles in A and y is number of white marbles in B then

x + y = 30.

We need to find out x/3 + y/4 or (4x+3y)/12 = (x + 90)/12

In order for the above expression to be integer, (x+90) should be a multiple of 12.....this is possible for x=6, 18, ........

or x/3 = 2, 6, .....

Since 2 is not an answer choice.....6 should be the answer.
Director
Director
User avatar
Joined: 04 Jan 2008
Posts: 919
Followers: 52

Kudos [?]: 183 [0], given: 17

Re: marbles [#permalink] New post 29 Mar 2009, 08:59
Its 6

R:W:B wise

A will have ratio of---> 2:6:9
and B---------------> 1:4

Total White marbles =30=10(k)
so red marbel wise , A will have 6.

Bag A contains red, white and blue marbles such that the red to white marble ratio is 1:3 and the white to blue marble ratio is 2:3. Bag B contains red and white marbles in the ratio of 1:4. Together, the two bags contain 30 white marbles. How many red marbles could be in bag A?
==
_________________

math-polygons-87336.html
competition-for-the-best-gmat-error-log-template-86232.html

Senior Manager
Senior Manager
avatar
Joined: 08 Jan 2009
Posts: 332
Followers: 2

Kudos [?]: 71 [0], given: 5

Re: marbles [#permalink] New post 17 Apr 2009, 20:08
I have a question:

Why did we take the Number of marbles in BAG A and BAG B to be equal as K? It did not state in the question?

I both were different quantities they would be slit up as : 2x : 6x: 9 x

and BAG B as : 1y : 4y

then i took 6x + 4 y = 30 3x + 2y = 15

i took y = 1 x = 13/3 not possible
y = 2 x = 11/3 not possible
y = 3 x = 3 possible.

So i since x = 3 i got R = 6. Is my approach correct.
Intern
Intern
avatar
Joined: 29 Dec 2006
Posts: 32
Followers: 0

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

Re: marbles [#permalink] New post 17 Apr 2009, 20:43
tkarthi4u wrote:
I have a question:

Why did we take the Number of marbles in BAG A and BAG B to be equal as K? It did not state in the question?

I both were different quantities they would be slit up as : 2x : 6x: 9 x

and BAG B as : 1y : 4y

then i took 6x + 4 y = 30 3x + 2y = 15

i took y = 1 x = 13/3 not possible
y = 2 x = 11/3 not possible
y = 3 x = 3 possible.

So i since x = 3 i got R = 6. Is my approach correct.


because 30 is the quantity from both bags, you can use the same variable; i.e. 6x+4x=30, x=3. then use this ratio for both bags.
Manager
Manager
User avatar
Joined: 08 Feb 2009
Posts: 147
Schools: Anderson
Followers: 3

Kudos [?]: 32 [0], given: 3

Re: Ratio of Marbles [#permalink] New post 02 Jun 2009, 07:45
Combined Ratio of marbles in

Bag A \Rightarrow 2:6:9 \Rightarrow a multiple of 6. Let the while marbles = 6x

Let White marbles in Bag B = W_b

Let White marbles in Bag A = W_a

Let Red marbles in Bag A = R_a


Bag B has (30-6x), which is a multiple of 4.

If x = 1, W_b = 24, W_a = 6, \Rightarrow R_a = 2 , which is not in the solution.

If x = 2, (30-12) is not a multiple of 4

If x = 3, W_b = 12, W_a = 18, \Rightarrow R_a = 6 , which is IN the solution.

If x = 4, (30-24) is not a multiple of 4.

Thus, answer is D.
Manager
Manager
avatar
Joined: 30 May 2009
Posts: 220
Followers: 3

Kudos [?]: 56 [0], given: 0

Re: Marbel Ratios [#permalink] New post 09 Jul 2009, 13:19
Bag A contains red, white and blue marbles such that the red to white marble ratio is 1:3 and the white to blue marble ratio is 2:3. Bag B contains red and white marbles in the ratio of 1:4. Together, the two bags contain 30 white marbles. How many red marbles could be in bag A?

1
3
4
6
8

Solution - Combined ratio of Red:White:Blue marbles in bag A is 2:6:9.

And ratio of Red:White in Bag B = 1:4

So total white marbled in 2 bags combined = 30 (given)
=> 6x + 4x = 30
=> x = 3

Hence red marbles in Bag A = 2x = 2*3 = 6

I would go with D. Whats the OA?
Senior Manager
Senior Manager
avatar
Joined: 23 Jun 2009
Posts: 359
Location: Turkey
Schools: UPenn, UMich, HKS, UCB, Chicago
Followers: 5

Kudos [?]: 95 [0], given: 60

Re: Marbel Ratios [#permalink] New post 09 Jul 2009, 14:48
Answer is D.

SdRandom, there is an error in your solution.

Your ratios are right.
2/6/9 in A
1/4 in B
That makes
6x + 4y=30 This is where you have done wrong.
After it. We must look at the choices.
Red no's must be even (2/6/9 ratio)
So it may be 4, 6 or 8.
If red is 4 => whites in A becomes 12; whites in B becomes 18 (30-12) => 1/4 ratio becomes impossible thus 4 is wrong.
If red is 8 => whites in A becomes 24; whites in B becomes 6 => 1/4 ratio becomes impossible
When red is 6 => whites in A becomes 18; in B becomes 12 thus 1/4 ratio becomes possible
Director
Director
User avatar
Joined: 25 Oct 2008
Posts: 609
Location: Kolkata,India
Followers: 9

Kudos [?]: 196 [0], given: 100

Re: Marbel Ratios [#permalink] New post 17 Jul 2009, 18:28
Is my process correct?

A R:W:B =2:6:9
B R:W=1:4

Now.A+B has 30 white marbles.
Out of this 30 B has 4/5 x 30 = 24 marbles,therefore the rest 30-24=6 must be from A.:)
Hence,D.
_________________

countdown-beginshas-ended-85483-40.html#p649902

Manager
Manager
avatar
Joined: 16 Feb 2010
Posts: 225
Followers: 2

Kudos [?]: 77 [0], given: 16

Re: help please :) [#permalink] New post 29 Aug 2010, 16:54
spatel121990 wrote:
ALSO

Bag A contains red, white and blue marbles such that the red to white marble ratio is 1:3 and the white to blue marble ratio is 2:3. Bag B contains red and white marbles in the ratio of 1:4. Together, the two bags contain 30 white marbles. How many red marbles could be in bag A?

A) 1
B) 3
C) 4
D) 6
E) 8

Please explain. I did not understand the explanation given. Thanks :)



BAG A: R to W to B is 2 to 6 to 9
BAG B: R W is 1 to 4

white in both is 30 therefore using 4+6 = 10
30/10 = 3

therefore 3 *6 = 18 white in bag a
ration is 2 to 6 therefore if 18w, 18*2/6 = 6red

D
Re: help please :)   [#permalink] 29 Aug 2010, 16:54
    Similar topics Author Replies Last post
Similar
Topics:
10 Experts publish their posts in the topic Bag A contains red, white and blue marbles such that the red vigneshpandi 11 08 Sep 2010, 19:56
2 Experts publish their posts in the topic Bag A contains red, white and blue marbles such that the red to white rajesh04 8 01 Jul 2008, 10:25
38 Experts publish their posts in the topic A bag of 10 marbles contains 3 red marbles and 7 blue bmwhype2 28 06 Dec 2007, 14:24
Bag A contains red, white and blue marbles such that the red nxrfelix 5 28 May 2007, 19:12
A bag contains 10 marbles - 3 red, 2 green and 5 blue sumitsarkar82 7 27 Jul 2006, 00:25
Display posts from previous: Sort by

Bag A contains red, white and blue marbles such that the red

  Question banks Downloads My Bookmarks Reviews Important topics  

Go to page    1   2    Next  [ 31 posts ] 



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®.