It is currently 19 Oct 2017, 22:26

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

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

In the table above, what is the number of green marbles in J

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

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 41884

Kudos [?]: 128929 [0], given: 12183

In the table above, what is the number of green marbles in J [#permalink]

Show Tags

01 Oct 2012, 05:11
Expert's post
7
This post was
BOOKMARKED
00:00

Difficulty:

5% (low)

Question Stats:

90% (01:22) correct 10% (01:49) wrong based on 794 sessions

HideShow timer Statistics

In the table above, what is the number of green marbles in Jar R ?

(A) 70
(B) 80
(C) 90
(D) 100
(E) 110

Practice Questions
Question: 55
Page: 159
Difficulty: 600

[Reveal] Spoiler:
Attachment:

Table.png [ 40.01 KiB | Viewed 13089 times ]
[Reveal] Spoiler: OA

_________________

Kudos [?]: 128929 [0], given: 12183

Math Expert
Joined: 02 Sep 2009
Posts: 41884

Kudos [?]: 128929 [2], given: 12183

Re: In the table above, what is the number of green marbles in J [#permalink]

Show Tags

01 Oct 2012, 05:11
2
KUDOS
Expert's post
2
This post was
BOOKMARKED
SOLUTION

In the table above, what is the number of green marbles in Jar R ?

(A) 70
(B) 80
(C) 90
(D) 100
(E) 110

We need to find the value of $$z$$, while given that:

$$x+y=80$$;
$$y+z=120$$;
$$x+z=160$$.

Sum these 3 equations: $$2x+2y+2z=360$$ --> reduce by 2: $$x+y+z=180$$ --> since we know that $$x+y=80$$, then $$80+z=180$$ --> $$z=100$$.

_________________

Kudos [?]: 128929 [2], given: 12183

Senior Manager
Joined: 31 Oct 2011
Posts: 484

Kudos [?]: 223 [2], given: 57

Schools: Johnson '16 (M)
GMAT 1: 690 Q45 V40
WE: Asset Management (Mutual Funds and Brokerage)
Re: In the table above, what is the number of green marbles in J [#permalink]

Show Tags

01 Oct 2012, 05:19
2
KUDOS
To solve, I took the sum of the expressions as seen below:

X + Y = 80
Y + Z = 120
X + Z = 160
2X + 2Y + 2Z = 360

Dividing by 2 we get X + Y + Z = 180.

Since we know X + Y = 80 from Jar P, we can deduce that Z = 100. Since Z is the number of green marbles in Jar R we have our solution.

[Reveal] Spoiler:
Answer is D, 100

_________________

My Applicant Blog: http://hamm0.wordpress.com/

Kudos [?]: 223 [2], given: 57

Senior Manager
Joined: 24 Aug 2009
Posts: 499

Kudos [?]: 839 [1], given: 276

Schools: Harvard, Columbia, Stern, Booth, LSB,
Re: In the table above, what is the number of green marbles in J [#permalink]

Show Tags

01 Oct 2012, 20:22
1
KUDOS
x+y = 80 ---(1)
x+z = 160---(2)
z+y= 120---(3)
Subtract equation 1 from 2 & we get--> z-y = 80----(4)
Add equation (4) & (3) we get--> 2z= 200
z=100
_________________

If you like my Question/Explanation or the contribution, Kindly appreciate by pressing KUDOS.
Kudos always maximizes GMATCLUB worth
-Game Theory

If you have any question regarding my post, kindly pm me or else I won't be able to reply

Kudos [?]: 839 [1], given: 276

Intern
Joined: 30 Aug 2011
Posts: 19

Kudos [?]: 15 [1], given: 17

Location: United States
Concentration: General Management, International Business
Schools: ISB '15
GMAT 1: 680 Q46 V37
WE: Project Management (Computer Software)
Re: In the table above, what is the number of green marbles in J [#permalink]

Show Tags

04 Oct 2012, 00:41
1
KUDOS
x + y = 80 ......(1)
y + z = 120 .....(2)
x + z = 160 ......(3)

From (2) above, z=160-y .....Substitute value of z in (3)

==> x-y = 40 ....(4)

Solve (1) and (4), to get x = 60
==> y = 20
==> z = 100

Thus, number of green marbles in Jar R = 100 (Ans = D)

Kudos [?]: 15 [1], given: 17

Math Expert
Joined: 02 Sep 2009
Posts: 41884

Kudos [?]: 128929 [2], given: 12183

Re: In the table above, what is the number of green marbles in J [#permalink]

Show Tags

04 Oct 2012, 14:20
2
KUDOS
Expert's post
SOLUTION

In the table above, what is the number of green marbles in Jar R ?

(A) 70
(B) 80
(C) 90
(D) 100
(E) 110

We need to find the value of $$z$$, while given that:

$$x+y=80$$;
$$y+z=120$$;
$$x+z=160$$.

Sum these 3 equations: $$2x+2y+2z=360$$ --> reduce by 2: $$x+y+z=180$$ --> since we know that $$x+y=80$$, then $$80+z=180$$ --> $$z=100$$.

Kudos points given to everyone with correct solution. Let me know if I missed someone.
_________________

Kudos [?]: 128929 [2], given: 12183

Manager
Joined: 25 Jun 2012
Posts: 71

Kudos [?]: 132 [0], given: 21

Location: India
WE: General Management (Energy and Utilities)
Re: In the table above, what is the number of green marbles in J [#permalink]

Show Tags

05 Oct 2012, 03:19
x+y=80...(1)
y+z=120 ==> z=120-y
x+z=160 ==> z=120-x...(3)

120-x=160-y
==> x-y=40...(2)

sloving (1) & (2) we get x=60
put value of x=60 in eqn (3),

60+z=160
=> z=100 Ans

Kudos [?]: 132 [0], given: 21

Senior Manager
Joined: 13 Aug 2012
Posts: 458

Kudos [?]: 541 [0], given: 11

Concentration: Marketing, Finance
GPA: 3.23
Re: In the table above, what is the number of green marbles in J [#permalink]

Show Tags

10 Dec 2012, 04:43
$$x + y = 80$$ eq 1
$$y + z = 120$$ eq 2
$$x + z = 160$$ eq 3
______________
$$2x + 2y + 2z = 360 --> x + y+ z = 180$$ eq 4

Combine eq 4 and eq 1:

$$80 + z = 180 --> z = 100$$

_________________

Impossible is nothing to God.

Kudos [?]: 541 [0], given: 11

Senior Manager
Joined: 15 Aug 2013
Posts: 302

Kudos [?]: 82 [0], given: 23

Re: In the table above, what is the number of green marbles in J [#permalink]

Show Tags

13 Apr 2014, 08:52
Bunuel wrote:
SOLUTION

In the table above, what is the number of green marbles in Jar R ?

(A) 70
(B) 80
(C) 90
(D) 100
(E) 110

We need to find the value of $$z$$, while given that:

$$x+y=80$$;
$$y+z=120$$;
$$x+z=160$$.

Sum these 3 equations: $$2x+2y+2z=360$$ --> reduce by 2: $$x+y+z=180$$ --> since we know that $$x+y=80$$, then $$80+z=180$$ --> $$z=100$$.

Kudos points given to everyone with correct solution. Let me know if I missed someone.

Are we always allowed to sum the 3 equations? Do we need to have some commonalities to be able to sum the equations?

Kudos [?]: 82 [0], given: 23

Manager
Status: suffer now and live forever as a champion!!!
Joined: 01 Sep 2013
Posts: 147

Kudos [?]: 71 [0], given: 75

Location: India
GPA: 3.5
WE: Information Technology (Computer Software)
Re: In the table above, what is the number of green marbles in J [#permalink]

Show Tags

13 Apr 2014, 21:16
X+Y =80 --------- (1)

Y+Z =120 -------- (2)

X+Z =160 -------- (3)

Subtract (3) -(1)

we get

Z - Y = 80 -----------(4)

ADD (4) and (2) equations,
Z=100;

Hence D.

Kudos [?]: 71 [0], given: 75

Math Expert
Joined: 02 Sep 2009
Posts: 41884

Kudos [?]: 128929 [0], given: 12183

Re: In the table above, what is the number of green marbles in J [#permalink]

Show Tags

14 Apr 2014, 01:30
russ9 wrote:
Bunuel wrote:
SOLUTION

In the table above, what is the number of green marbles in Jar R ?

(A) 70
(B) 80
(C) 90
(D) 100
(E) 110

We need to find the value of $$z$$, while given that:

$$x+y=80$$;
$$y+z=120$$;
$$x+z=160$$.

Sum these 3 equations: $$2x+2y+2z=360$$ --> reduce by 2: $$x+y+z=180$$ --> since we know that $$x+y=80$$, then $$80+z=180$$ --> $$z=100$$.

Kudos points given to everyone with correct solution. Let me know if I missed someone.

Are we always allowed to sum the 3 equations? Do we need to have some commonalities to be able to sum the equations?

Yes, we can sum/subtract/multiply equations. I think you are mixing equations with inequalities, for which there are specific rules.

Hope this helps.
_________________

Kudos [?]: 128929 [0], given: 12183

Senior Manager
Joined: 15 Aug 2013
Posts: 302

Kudos [?]: 82 [0], given: 23

Re: In the table above, what is the number of green marbles in J [#permalink]

Show Tags

28 Apr 2014, 21:27
Bunuel wrote:
russ9 wrote:
Bunuel wrote:
SOLUTION

In the table above, what is the number of green marbles in Jar R ?

(A) 70
(B) 80
(C) 90
(D) 100
(E) 110

We need to find the value of $$z$$, while given that:

$$x+y=80$$;
$$y+z=120$$;
$$x+z=160$$.

Sum these 3 equations: $$2x+2y+2z=360$$ --> reduce by 2: $$x+y+z=180$$ --> since we know that $$x+y=80$$, then $$80+z=180$$ --> $$z=100$$.

Kudos points given to everyone with correct solution. Let me know if I missed someone.

Are we always allowed to sum the 3 equations? Do we need to have some commonalities to be able to sum the equations?

Yes, we can sum/subtract/multiply equations. I think you are mixing equations with inequalities, for which there are specific rules.

Hope this helps.

Thanks for clarifying.

Just to confirm one of your comments above -- "Yes, we can sum/subtract/multiply equations." -- would this be valid for the problem even if one of the equations didn't have any common variables. What I mean is, if the equations read:

$$x+y=80$$;
$$a+b=120$$;
$$x+z=160$$.

Can we still add the 3?

Kudos [?]: 82 [0], given: 23

Math Expert
Joined: 02 Sep 2009
Posts: 41884

Kudos [?]: 128929 [0], given: 12183

Re: In the table above, what is the number of green marbles in J [#permalink]

Show Tags

29 Apr 2014, 00:58
russ9 wrote:
Bunuel wrote:
russ9 wrote:
Are we always allowed to sum the 3 equations? Do we need to have some commonalities to be able to sum the equations?

Yes, we can sum/subtract/multiply equations. I think you are mixing equations with inequalities, for which there are specific rules.

Hope this helps.

Thanks for clarifying.

Just to confirm one of your comments above -- "Yes, we can sum/subtract/multiply equations." -- would this be valid for the problem even if one of the equations didn't have any common variables. What I mean is, if the equations read:

$$x+y=80$$;
$$a+b=120$$;
$$x+z=160$$.

Can we still add the 3?

_______________________
Yes.
_________________

Kudos [?]: 128929 [0], given: 12183

Senior Manager
Joined: 15 Aug 2013
Posts: 302

Kudos [?]: 82 [0], given: 23

Re: In the table above, what is the number of green marbles in J [#permalink]

Show Tags

29 Apr 2014, 07:47
Bunuel wrote:
russ wrote:

Can we still add the 3?

_______________________
Yes.

Thanks -- that clarifies a lot!

Kudos [?]: 82 [0], given: 23

Current Student
Joined: 13 Feb 2011
Posts: 104

Kudos [?]: 48 [0], given: 3385

Re: In the table above, what is the number of green marbles in J [#permalink]

Show Tags

20 Aug 2014, 23:47
Another approach can be back solving by taking a value from choices for z and finding x and y to see if they make sense per the table.

Kudos [?]: 48 [0], given: 3385

SVP
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1853

Kudos [?]: 2621 [0], given: 193

Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Re: In the table above, what is the number of green marbles in J [#permalink]

Show Tags

09 Sep 2014, 22:05
The table provided in this question was a boon for me. See how below.....
Attachment:

Table.png [ 45.65 KiB | Viewed 8366 times ]

1. Replaced y with (80-x). The equation remains intact on "Jar P" row

2. Copied (80-x) in "Jar Q" row.

These 2 steps directly eliminates x & y

3. Adding rows "Jar Q" & "Jar R"

2z+80 = 280

z = 100

_________________

Kindly press "+1 Kudos" to appreciate

Kudos [?]: 2621 [0], given: 193

Intern
Joined: 18 Oct 2013
Posts: 3

Kudos [?]: [0], given: 20

Re: In the table above, what is the number of green marbles in J [#permalink]

Show Tags

21 Nov 2014, 03:28
From the given table we could make equations like
Equation 1. Given x+y=80 ----> x=80-y
Equation2. Given y+z=120
Equation3. Given x+z = 160
Substituting the value of x in Equation 3 from Equation 1
Equation 4. (80-y)+z=160 ----> -y+z = 80
Adding Equation 2 and Equation 4
2z=200 ---> Z=100.

Kudos [?]: [0], given: 20

Director
Joined: 10 Mar 2013
Posts: 593

Kudos [?]: 460 [0], given: 200

Location: Germany
Concentration: Finance, Entrepreneurship
GMAT 1: 580 Q46 V24
GPA: 3.88
WE: Information Technology (Consulting)
Re: In the table above, what is the number of green marbles in J [#permalink]

Show Tags

22 Jul 2015, 09:52
just substract from the first equation the 2nd and the 3rd you'll get --> x+y-y-z-x-z = -200 ->x,y cancel out and Z=100 (D)
_________________

When you’re up, your friends know who you are. When you’re down, you know who your friends are.

Share some Kudos, if my posts help you. Thank you !

800Score ONLY QUANT CAT1 51, CAT2 50, CAT3 50
GMAT PREP 670
MGMAT CAT 630
KAPLAN CAT 660

Kudos [?]: 460 [0], given: 200

Senior Manager
Joined: 28 Jun 2015
Posts: 300

Kudos [?]: 107 [0], given: 47

Concentration: Finance
GPA: 3.5
Re: In the table above, what is the number of green marbles in J [#permalink]

Show Tags

22 Jul 2015, 09:56
x+y = 80 (i)
y+z = 120 (ii)
x+z = 160 (iii)

from (i) and (ii):
z-x = 40
z+x = 160

so, z = 100, x = 60, y = 20.

Ans (D).
_________________

I used to think the brain was the most important organ. Then I thought, look what’s telling me that.

Kudos [?]: 107 [0], given: 47

Target Test Prep Representative
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 1545

Kudos [?]: 836 [0], given: 5

In the table above, what is the number of green marbles in J [#permalink]

Show Tags

30 May 2016, 05:32
Bunuel wrote:

In the table above, what is the number of green marbles in Jar R ?

(A) 70
(B) 80
(C) 90
(D) 100
(E) 110

We can create three equations from the information presented in the table.

Equation 1: x + y = 80

Equation 2: y + z = 120

Equation 3: x + z = 160

These equations present us with a good opportunity to use the “combination method” to solve multiple equations. Here, we can add equations together. Because we need the number of green marbles in jar R, we need to determine the value of z.

We can start by multiplying equation 1 by -1.

-1(x + y = 80) = -x – y = -80

Next, we add this equation to equation 2. So we have:

-x - y = -80 + (z + y = 120) = z – x = 40

Now we can add z – x = 40 to equation 3. So we have:

–x + z = 40 + (x + z = 160)

2z = 200

z = 100

_________________

Jeffery Miller
Head of GMAT Instruction

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Kudos [?]: 836 [0], given: 5

In the table above, what is the number of green marbles in J   [#permalink] 30 May 2016, 05:32

Go to page    1   2    Next  [ 22 posts ]

Display posts from previous: Sort by

In the table above, what is the number of green marbles in J

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics

 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®.